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- [UNDEFINED Terms] [11 Point; notation Point A is labeled with a capi tal le tter, A in thi s ca se [2J Line; notation Line KM is labeled cither KM or MK or li n e I [3J Plane; notation Plane N is labeled eit her plane 11 or pl a ne AB C if point s A, B, and C are on plane /I [DEFINED Terms] [GENERAL Terms] [1J i( C rlCJI Jl" ) Shapes are the same shape and size [21 (II 11"1' Shapes arc the same shape, but can be different sizes [3J i.q Jdl Sets of po i nts or numerica l measurements arc ex actly t he same [4J JIllor! Describes t he result when all of the points are put to g ether [5J (II rs C 101) Describes t he points where indicated sh a pes touch [6J p c The set of all points 111"'4'. [1J Collinear points are on t he sam e line [2J Non colill c I points are not on the same line [3J Inter II 9 l ines have one and on ly one point in common [4J PIp I dlcul, r lin es intersect and form 90° angles at the intersection; 1. [5J k w lines are not in the s ame plane , never touch, and go In different directions [61 Tlan versa I lines intersect two or more co-pl a nar lines at diff erent points [7J P r II I lines are co-planar (in the same . plane) , share no points in c ommon, do not intersect , go in the same direction and never touch; II [LINE Segments] [1J The set of any 2 points on a line an d al l of the collin e ar poin ts be tw ee n them; AB where A and B are the en dpoints of the Iine s egment [2J The I CJth is the distance between the 2 endpoints; it is a numerical va lu e; AB means the length of A B 1'.'. [1J The set of c ollinea r poin ts g oin g in o ne direction from onc poin t ( the endpoi nt of t he ray) on a li ne ; nota ti on : AS w here A is the endpoint; not ice lIB *BA because t hey have differe nt endpoin ts a nd co nta in different p oin ts on t he li ne [2J Oppo It r y are colline ar, s hare o nly a common e ndpoin t an d go in o ppos ite direc ti ons [ANGLES] [1J Th e union of tw o ra ys t hat share one and only one point , the endpoin t of t he ra ys a. T he Sid of t he angle are the rays a nd t he v r x is t he endpoint of the ra ys b. The Interrol is all t he point s bet ween the two side s of the angle c. LABe where B is the vertex or simply IB if there is only one angle with vertex B [2J Ov Ilapping angl s share some comm on int erior p oints [3J An ac Jte angle mea s ures less than 90° [4J An obtuse angle measures more than 90° [5J A right angle me a sures exactly 90°; it is indicated on diagrams by drawing a square in the c orner by the v ertex of the angle [6] A straight angle measures ex a ctly 180° [7J Complem ntary ngles are two an gle s whose me asure s total 90° [8J Supplementary angles are two an gles whose me asures tota l 180 0 [9J Vertical angl s are t wo ang les that sha re only a e ommo n v ertex a nd whose s ide s form lines [10JAdjacent angles are t wo angles t hat sha re e xaetly one v ertex and one side, but no com mo n int e rior points ; i.e., t hey do not overlap [11J An ngle bisector is a ray or a line t hat contain s the vertex of the angle , is in the interior, a nd separates the a ngle into two a djacent angles with equal measures [3] The n idpoint is a point exactl y in the mid dle of the two endpoints [4] The bisector intersec ts a line segment at its m idpoint [5J T he perpendicular bls tor inter s ects a line se gmen t at its midpoint and forms 90° angl es at the intersection 1 [ TRANSVERSAL LINE Angles] [1J In erlor ilngll are formed with thc rays from the 2 li nes and the tra nsversal, such t hat t he interior region s of the angles are loc ated be t ween the 2 lines [2J Alt rn 1 e II trior mgl arc i nte r ior c a ng les w it h di f ferent vertexes and interior regions on opposite sides of the trans versa l [3J ,1m lel II t nor ngle are inter ior angles wi th different vertexes and inte r ior reg ions on th e sa me side of the t ransver sal [4J Ex I lor, r gl are formed with rays from the 2 lines and the transvers a l, such t hat thc in terior re gio ns of the a ngle s are n ot between the 2 l ines [51 Altern t xt riar lnql are exterio r an gles with di fferent vertexes and in terior regions on opposite sides of the iIIr.. transversa l ,.. [6] Carr pondlng angl h ave differe nt = v ertexes ; the ir i ntcr ior regions ar e on thc ... same side of the transversa l and in the " same positions relative to the lines and m the transversa l; one of th e pair of Z corresponding angles is an inte ri or anglc and the oth er is an exterior angle [POLYGONS] [1J Polygons arc plan (flat), closed sh apes that are formed by l ine seg m ents tha t inter e ct only at thcir endpoints a. Not Th cy are nam ed by listing the endpoints of th e l ine s eg m ents in ord er, g oin g either clockwise or co unt ercl oc kwisc, sta rting at anyo ne of the endpoi nts b. The sides are li ne egments c. The int riar is all of t he points e nclo s ed by the sides d. T he xterior is all of t he point · on the plane of the polygo n, but neithe r on the si de s n or in the int erio r e. The vertic (or vertexes) are th e iIIr.. endpoi nts of the li ne seg ments ,.. f. Inc ludc all the points on the s id es (line = seg ment s) and the ve r tices ... g. The int rior angl or a polygon have " the sa me vertices as the ver ticcs of th e m polygon , h ave side s tha t cont ain the Z side s o r t he po ly go n, and h ave in te ri or regions that co ntain the interior of the po lygo n- every pol ygon has as many interior a ng les as it has vertices

15FORMULAS GEOMETRICAS

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-[UNDEFINEDTerms] [11Point; notation PointA is labeled wi th acapi tal letter,A in thi s case[2JLine; notation Line KM is labeledcitherKM or MK orli ne I [3JPlane; notation PlaneN is labeledeit herplane 11 orpl aneABC ifpointsA, B, andC are on plane /I [DEFINEDTerms] [GENERAL Terms][1J i( C rlCJI Jl" ) Shapes arethesame shapeand size[21 (II 11"1' Shapesarcthesameshape, butcanbedifferentsizes[3J i.qJdl Sets of po ints or numerica lmeasurements arc exactly t he same[4J JIllor! Describesthe resultwhen all ofthe pointsare puttogether[5J (II rs C 101) Describes the pointswhere indicated shapes touch[6J p c The setofall points111"'4'. [1J Collinear pointsareon the same line[2J Non colill cI points are not on thesame line[3J Inter II 9 lines have one and on lyonepointin common[4J PIp Idlcul, r lines intersect and form90angles atthe intersection; 1.[5J k w lines are not in the same plane,never touch, and go In differentdirections[61 Tlan versaI lines intersect two or moreco-pl anarlinesatdiffere nt points[7J P r II I lines are co-planar (in the same .plane) , share no points in common, donot intersect , go in the same directionand nevertouch; II[LINESegments][1J The set ofany 2 points on a line and allofthe collinear points between them;ABwhereAandB are the endpoi nts ofthe Iinesegment[2J The I CJth is the distance between the 2endpoints; it is a numerical va lue; ABmeans the length ofA B1'.'.[1J The set ofcollinea r point s going in onedirection from onc point (the endpoi nt oftheray) on a li ne ;notati on: ASwhereA istheendpoint; not ice lIB *BAbecausetheyhave different endpoint s and conta indifferent points on the li ne[2JOppo It r y arecollinear,shareonlyacommon endpoin t and go in oppos it edirecti ons[ANGLES] [1J The union oftwo rays thatshare one andonly one point, the endpoint ofthe raysa. The Sid ofthe angl e are the rays andthev r x is the endpointoftheraysb. The Interrol is all t he points betweenthe two sides ofthe anglec.LABewhere B is thevertex orsimply IB ifthere is onl y one angl e with vertex B[2J Ov Ilapping angl s share somecommon int erior points[3J An ac Jte angle measures less than 90[4JAn obtuse angle measures more than90[5J A right angle measures exactly 90;it isindicated on diagrams by drawing asquare in the corner by the vertex of theangle[6] A straightangle measuresexactly 180[7J Complem ntary ngles are two angleswhose measures total 90[8J Supplementary angles are two angleswhose measurestotal 1800[9J Vertical angl s are twoangles that shareo nly a eommon vertex and whose s idesform lines[10JAdjacent angles are two angles t hatsha re exaetly one vertex and one side,but no common interior points ; i.e., theydo notoverlap[11JAn ngle bisector is a ray ora line thatcontains the vertexofthe angle, is in theinterior, and separates the angle into twoadjacent angles with equal measures[3] The n idpoint is a point exactl y in themiddle ofthetwo endpoints[4] The bisector intersect s a line segmentat its midpoint[5J The perpendicular bls tor intersectsa linesegment at its midpointand forms90angl es at the intersection1[TRANSVERSALLINE Angles][1JIn erlor ilngll are formed with thc raysfrom the 2 li nes and the transversal,suchthat the interiorregions ofthe anglesarelocated between the 2 lines[2J Alt rn 1 eII trior mgl arc inter ior cangles wit h di fferent vertexes andinterior regions on opposite sides oft hetransversal[3J ,1m lel II t nor ngle are inter iorangl es wi th different vertexes an dinterior regions on th e same s ide of thet ransversal[4JEx I lor,r gl are formed with raysfrom the 2 linesand the transversal, sucht hat thc in terior regions ofthe angles arenot bet ween t he 2 lines[51Altern t xt riar lnql are exteriorangles with different vertexes andinterior regions on opposite sides ofthe iIIr..tra nsversa l ,..[6] Carr pondlng angl have different =vertexes ; the ir intcriorreg ionsare on thc ...same side ofthe transversa l and in t he "same positions relative to the lines and mthe transversal; one of th e pair of Zcorrespondingangles is an interi or anglcand the other is an exteriorangle [POLYGONS] [1JPolygons arc plan (flat), closed s hapesthat are formed by l ine segments tha tinter ect only atthcirendpointsa. Not Thcy are named by listing theendpoints of the l ine segments inorder, going either clockwise orcountercl oc kwisc, sta rt ing at anyoneofthe endpointsb.The sidesare line egmentsc. The int riar is all of t he pointsenclosed by the s idesd.The xterior is all of the point on theplane ofthe polygon, but neithe r ont he si des nor in t he int eriore.The vertic (or vertexes) are the iIIr..endpoi nts ofthe li ne segments ,..f.Inc ludc a llthe pointson thes ides( line =segment s) and the vertices ...g.The int rior angl or a polygon have "the same vert ices as the verticcs ofthe mpolygon, have sides that cont ain the Zsides o r the polygon, and have in teri orregions that conta in the interior ofthe polygon- every pol ygon has as manyinteriorangles as ithas verticesPolygons(continued) h.Consecutive interior angles havevert ices that are endpoints ofthe samesideofthe polygonI.The exterior angles are formed whenthe sides of the polygon are extended;each has a vertex and one si de that arealso a vertex and contain one side ofthe pol ygon; the second si de of theexterior ang le is the extension oftheotherpolygon sidecontainingtheanglevertex; the interioroftheexteriorangleis part of the exterior region of thepolygon; exteri or angles are s upp le-ments oftheiradjacent interioranglesj.Diagonals of a polygon are linesegments wit h endpoints that arevertices of the polygon, but thedi agonals are notsides ofthe polygon[2) CONCAVEpolygons have at least oneinteriorangle measuring morethan 1800[3) CONVEXpolygon s have no inter iorangles more than 1800and all interiorangleseach measure less than 180[4) REGULARpolygons haveall si de lengthsequal and a ll interi or angl e meas uresequal[5) CLASSIFICATIONSOFPOLYGONS a. Classifi ed by the number of si de s;eq ualto the nu mber of verticesb. side lengths and angle measuresarc not necessa rily equal un les s theword " regular" is also used to name thepolygonc. Categories Triangles havethree sides Quadrilaterals have four sides Pentagons have five sides Hexagons have six si des Heptagons have seven sides Octagons havee ight sides Nonagons have nine si des Decagons have ten si des n- gons have n s ides[CIRCLES] [1) The set ofpoints in a pla ne eq uid is tan tfrom the center ofthe ci rcle, which liesin the inter ior ofthe circl e and is not apointon the circl e; 360[2) A radius is a linesegmentwhoseendpointsare thecent erofthecircleand any poi ntonthe ci rcle; the length of a radius is thedistanceofeach pointfrom thecenter[3) A chord is a li ne segment whoseendpoints arc 2 points on the ci rcle[4] A diameter is a chord that contains thecenterofthe ci rcle; the lengthofadi ameterIS the distance from one pointto another on the circle, going throughthecenter15) A secant is a li ne intersect ing a circle intwo poi nts [6) SPECIALPOLYGONS a.Triangles Polygons with 3 sides and 3 vertices;the symbol for a triangle is tri angleABC is written An altitude (height) is a line segmentwith a vertex ofthe triangle as oneendpoint and the point on the linecontaining the opposite side of t hetriangle where the altitude is perpen-diculartothat line; everytriangl e has 3alt itudes A base is a side ofthe triangle on theline perpendicular to an altitude; everytriangle has 3 bases Formulaforarea A =tllb or iI=thb wherea=altitude,b=base orwhere h=hei ght (altitude), b=basein2 ways,bysidelengths and by anglemeasurements a]When classified byside lengths:Scalene have no side lengths=, Isosceles have at least 2 sidelengths equal, Equilateral have all 3 side lengthsequal; note it is also an isoscel estriangleb]When classified byangle measure-ments:Obtuse have exactly one anglemeasurement more than 900 Right have exact ly one anglemeasurementequal to 9090 Acute have all 3 angles less than0; note that if all 3 angles areequal, then t he tr iangle is calledequiangularIsosceles triangles a]The vertex angle has s idescontain ing the two congruent s idesofthe triangleb]The base is the side with a differentlength than the other two sides; not[6] Atangentisa line thatis co-planarwith acircle and intersects it at one point only,call ed the pointoftangencya.A cornmon tangent is a line that istangentto 2 co-planarcircles Common internal anqents intersectbetween the twocircles Common external tangents do notintersectbetween the circl esb .Two circ les are tangent when they areco-planar and share the same tangentline atthe same pointoftangency; theymaybeexternallyorinternally tangent[7) Equal Circles haveequal-length radii[8) Concentric circles lie in the same planeand have the samecenter2necessarily the side on t he bottomofthe triangl ec] The base angles ofan isoscelestriangle have t he base contai ned inone oftheir sides ; they are alwaysequal in measureRight Triangles a] The hypotenuse is opposi tethe ri ght angle and is the longestsideb ]The legs arc the 2 sides that arcnot the hypoten use; the linesegments contained in the sides o ft he right angleb.Quadrilaterals 4-sided polygons Have 2 diagonal s and 4 vert icesrap zOld have exactl y one pa ir ofpara ll e l sides ; there is never moret han onepairofpara ll e lsidesa] Para ll el sides : bab]Non-para llel sides :legsc] The 2 angles wi th vertices that arcthe endpoint s o f the same base arccall ed ba angld]lsosceles trapeZOids havelegs that arc the same length Parallelograms have 2 pairs ofparallel s idesa] Rectangl s have 4 ri ghtanglesb]Rhombus s (s ing. rhombus) have4 sides equa l in lengthc] Squares have 4 equal sides and 4equal angles ; therefore, eve rysquare is both a recta ngle and arhombus[9] An inscribed polygon has vertices thatare po ints on t he circl e; in th is sa ill esi tuation, t he ci rcl e is c ircumscribed aboutthe polygon110] A circumscribed polygor has sides thatarc segments of tangents to theci rcle; i.e.,the s ides of the polygon each containexac t ly one poi nt on the circle; in th issame sit uati on, the circle is inscribed inthe polygon[11) Anarc is partofaci rclea.A erni ircl is a n arc whoseendpoints are the endpo ints o f adiameter; 180; exactl y th ree pointsmust be u.' cd to na me a scmiei rcle;notation: AiJC where A and C are t heendpoints o fthe diameterThrough a point not on a line, exactlyone perpendicularcanbe drawn to thelineThe shortest dist ance from anypoint to a line or to a plane is thepcrpcndiculardistanceThrough a poi nt not on a line, exactlyone parallel can bedrawn to the lineParallel lines are everywhere the samedistanccapartIfthree or more parallel lines cut offequal segments on one transversal, thenthcy cut off cqual segmcnt s on cvcrytransversal they sharcA linc anda planc are parallel iftheydonot touch orintcrsectTwo or more planes are parallel if theydo nottouch orintersectAnglesaremeasured usinga protractoranddegree mcasurements: There are 3600in acircle; placing the center ofa protractor atthe vcrtcx ofan anglc and counting thedegreemeasure is li ke puttingthe vertexofthe angle at the center of a circle anc!comparing the angle measure to thedegreesofthecircle9()1 00If two angl es are compl ements of thesame angl e, then they arc equal Inmeasure (congruent)If two angles arc compl ements ofcongruentangles, then theyare congruentIf two angl es are supplements of thesameangle,then they are congruentb .A minor arc length is less than thelengt h of t he semicircl e; only twopoints maybe used to name a minor'arc ;notation: DEwhere D and E aretheendpoints ofthe arcc.A majorarc lengt h is more than thelength of the semi c irc le; exac t lythree points arc used t o namc amajor arc; notation: FCfjwhere Fand H are the endpoints ofthe arc[12JAcentral angle vertex is the cent erofthe c ircle with si des that containradiiofthe circle[13JA inscribed-angle vert ex is on acircle with sides that contain chordsofthe circleIf two parallcl plancs arc bothintcrsccted by a third plane, thcn thclinesofintersection are parallelIf a point lies on the perpendicularbisectorofa line segment,thenthepointis equidistant (equal distances) from thecndpoints ofthe line segmentIf a point is equidistant from t heendpoints ofa line segment , then thcpoint lies on thc perpendicular biscctorofthe line segmentTo trisect a line segment, separate itinto three other congruent (equal inlength) line segments, suchthatthe sumofthe lengths ofthe three segments isequal to the length ofthe original linesegmentIf two angles are supplements ofcongruentangles, then theyarecongruentVert ical angles are congruent and haveequal measuresIfa point lies onthebisectorofan angle,then the point is (equaldistances)from the sidesofthe angleDistance from a point to a lineis always the length of the perpen-dicular line segment that has the poi ntas oneendpoint and a pointon the lineas the otherIfa point is equidistant from the sides ofan angle, then the point lies on thebiseetorofthe angleAn angle is trisected by rays or lines thatcontainthe vertexofthe angleandseparatethe angle into three adjacent angles (inpairs)thatall haveequalmeasures[POSTULATES] Statements that have been acceptedwithoutformal proof[1J A linecontainsat least2points,andany2points locate exactlyone line[2J Any 3 non-collinearpoints locate exactlyoneplane[3] A lineandonepointnotonthe line locateexactlyone plane[4J Any3 points locateat leastoneplane[5J If 2 pointsofa lineare in a plane,thentheline is in the plane[6] If2 points are in a plane, then the linecontainingthe 2pointsis also in the plane[7] If2 planes intersect, then the intersectionis a line3If two rays do not int ersect , then theunion of the rays is s imply a ll of thepoints on both raysIftwo rays intersect in one and only onepoint, but not at the endpo int, then theunion is all ofthe points on both rays;theintersection is that one point where theytouchIftwo rays intersect in one and onl y onepoint, the endpoint, then the uni on is anangle; the int ersection is the endpointIft wo rays intersec t In more than onepoint, then the union IS a line; theintersection is a line segmentA BAB BAAB BAIf lines are para ll e l, th en th e a lt erna teinter ior angl es of a tra nsve rsa l arecongruentIf the a lt ern ate interi or angles of atransversal are congruent. then the linesare para ll elIflines are para ll e l, t hen the same s idcinteri or angl es of a trans ve rsa l aresuppl ementaryIf th e sa me-s ide int e ri or angl es of atrans versal are s uppl eme ntary, the n theI inesare para ll e lIf lines are para ll e l, then thecorrespond ing angles ofa transversalarecongruentIf the corres ponding ang les o f a trans-ve rs a l are congruent, then t he lines areparall elIf lines a re parall e l, then th e a lte rn ateexterior angles of a t ransversal arecongruentIf the al ternat e exte rior ang les o f atransversa l are congruent, then the linesare parallelIfa transversal is perpendi cular to one o ftwo parall el lines, then it is al so perpen-----ndiculartothe other------m alternat Jr.: 4- 6; 5- 3same-Side interior 4- 5; 3- 6correspondng':s: 1- 5; 4- 8;3- 7; 2- 6alternateexterior 1- 7; 2-8ductrnalThe sum ofthe measures ofthe interior '1The 3 bisectors of the angles of aWhen an altitude is drawn to theanglesofaconvexpolygonwith nsides is triangle intersect in onepoint, which ishypotenuseofa righttriangle(n-2)180 degrees equidistantfromthe 3sidesThe two triangles formed areTo find the measureofeach interior The ofthesimilarto each otherand to theangleofaregularpolygon,findthe sumof sides of a triangle intersect in oneoriginal right triangleall ofthe interiorangles and dividebythe point,equidistantfrom the 3verticesThe altitude is thenumber of interior angles, thus, the The medians (line segments whosebetween the lengths offormula (TI- 2) 180 endpointsareonevertexofthe trianglethe two segments of theTIand the midpoint ofthe side oppositehypotenuseThe sum ofthe measures ofthe exteriorthat vertex) ofa triangle intersect inEach leg is the geometric meanangles ofany convex polygon, using oneone point two-thirds ofthe distancebetweenthe hypotenuseand theexteriorangleateachvertex, is 360fromeachvertex to themidpointofthe sumlength of the segmcnt oftheIroppositeside hypotenuse adjacent (touches) The3-angletotal measurement=180Iftwosidesofatriangleare unequal inmberIf two angle measurements of onelength, then the opposite angles arcto the legidcstriangle=two angle measurements ofunequal andthelargerangleisoppositet .anothertriangle,thenthemeasurementsto the longer side; and conversely, ifIfthree sides ofofthethirdanglesarealso=two angles ofa triangle arc unequal ,one triangle are congruentto three Each angle ofan thenthesidesoppositethoseanglesaresides ofanother, then the triangles is 60unequaland the longerside is opposite are congruent Therecan be no more than one rightorthe largerangle I f two sides and obtuseangle in anyonetriangleThesumof thelengthsof anytwosides the included angle ofone triangle The acute angles ofa right triangle arcis greaterthan the length ofthe third are congruent to two sides and the complementaryside; the difference ofthe lengths ofincluded angleofanother. then the Themeasurementofan exteriorangle=any two sides is less than the length oftrianglesare congruent thesumofthemeasurementsofthetwothe thirdsideIftwo angles andremote (not having the same vertex asthe included side ofone triangle theexteriorangle) interioranglesAnequilateraltriangleis alsoequian-are congruent to two angl es andI ftwosidesofatriangleareequal ,thengular; and, an equiangular triangle isthe included side ofanother, thenthe angles opposite to those sides arealso equilateralthetriangles arecongruentalsoequal; and, iftwo anglesareequal ,An equilateral triangle has three 60-Iftwoanglesandathen the sides opposite those angles aredegreeanglesnon-included side ofone trianglealsoequalThebisectorofthevertexangle ofanare congruent to the twoIftwo sidesisoscelestriangle is the perpendicularcorresponding angles and non-ofone triangle are equal in length tobisectorofthebaseofthetriangle included side ofanother, then the two sides ofanother, but the included trianglesare congruent angle ofone triangle is largerthan theIn a right Ifthe hypotcnuse included angle ofthe other triangle,triangle, , where ., and ' and one leg ofa right triangle are then the longer third side of thearethe lengthsofthe legsand is the triangles is opposite the largerincludedlengthofthe hypotenusecongruent to the hypotenuse and the corresponding leg ofanother.angleofthetrianglesIfthe square ofthe hypotenuse isIftwo sidesequal to thesumofthesquaresofthethen the two right triangles are ofonetrianglearc equal to twosidesofothertwo sides, then the triangle is acongruent another, but the third side ofone is longer than the third side ofthe other,Ifthe square ofthe longest side is Iftwo then the largerincludedangle(includedgreaterthanthesumofthesquaresof angles of one triangle arc between the two equal sides) isthe other two sides, then it is an congruent to two angles of opposite to the longer third side ofthetriangle; ifit is less than theanother. then the triangles are trianglessum ofthe squares ofthe othertwosimilar (same shape but not sides,then it is an trianglenecessarilythe samesi ze) If a line is parallel to one side andIn a 45-45-90 If theintersects the other two sides, then ittriangle, the legs have equal lengthssides ofone triangle are propor-divides those two sides proportionally,and the length ofthe hypotenuse istionaltothecorrespondingsidesof and creates2 similartriangles12timesthe length ofoneofthe legs another, then the triangles areI fa anangleofatriangle,itIn a 30-60-90similardividesthe opposite side into segmentstriangle,the length ofthe shortestlegIftwoproportional to theothertwosidesis 1/2 the length ofthe hypotenuse,sides ofone tri angle are propor-The line segment that joins theandthe lengthofthe longerleg is 13 tional to two sides ofanother andmidpointsoftwo sidesofa triangle hastimesthe length oftheshortestleg the included anglcs of each two properties:The midpoint ofthe hypotenuse ofatriangle are congruent, then theIt is to the third side,andright triangle is equidistant from thetriangl esare similarIt is ofthethird sidethreevertices4I

ATERALS 4The (the line segmentwhose endpoints are the midpointsZ ofthe2 non-parallel sides) is parallelIII tothebases,andits length is equal tohalfthe sum ofthe lengths ofthe 2D-basesC The may be calculated byaveragingthe lengthofthe basesandT mUltiplying by the height (altitudeothat is the length ofthe line segmentP that forms 90-degree angles with thed bases); thus , theformula:A(hi(hi +h, )h et where the 2bases are b1 and b2 andthe height is h Two angles with vertices that are theendpoints of the same leg of atrapezoid areAll 4 interior angle measures ofalltrapezoids total 3600Thebase anglesare congruent(has congruentlegs) Opposite angles are suppl e-mentary Opposite sides are parallel andcongruentOpposite angles arc congruentAll 4 interiorangles total 3600Consecutive interior an g les (thei rvertic es are endpoint s for the sameside) arc suppl ementaryDi agonal s bi secteach otherA quadril ateral is a parallelogram if:[CIRCLES] Ifa line is to a circle, then itis perpendicular to the radius whoseendpoint i s the point oftangency (thepoint where the tangent line intersectsthe circle)/.If t wo tangents to the same circleintersect in the exteriorregion, then theline segments whose endpoints are thepointofintersection ofthe tangentlinesandthetwo pointsoftangencyareequalin length; or, line segments drawnfrom a co-planar exterior point of acircle to pointso ftangencyon thecircleare congruentOne pair of opposite sides iscongruentand parallelBoth pairs ofopposite sides arecongruentBoth pairs of opposite anglesare congruentThe diagonals bisecteachotherThe can be calculated bymultiplying the base and theheight; that is, A=bh=hb Since opposite sides arebothparallel andequal, any sidecan be the base; the height(altitude) is any line segmentperpendicularto the base whoseendpoints arc on the base andthe sideoppositethe baseParallelograms with 4 rightanglesDiagonals are congruent andbisecteachotherThe equal s Iworhb where 1= length, w=width,h=height, and b =baseIf the4 sidesare all equal,thenthe rectangle is more specifi-callycalled a squareParallelograms with 4 congruentsidesOpposite angles are congruentAll 4 angle measures total3600 Any 2consecuti ve angles arcsupplementaryIf a line in the plane of a circl e isperpendicular to a radius at its outerendpoint. then the line is tangent to thecircleThe measure ofa is equal tothe measureofits central angleThemeasure ofa is 1800The measure ofa is equal to3600mlllus the measure of itscorrespondingminorarcIn the same circle or in equal circl es,equa I chords have equal arcs and equalarcs have equal chordsA perpendicular to a chordbisectsthe chordand its arcIn the same circle or in equal circles,congruent chords are the same distancefrom the center, and chords the samedistance from thecenterarccongruent5If4 int erior angles eachequal 900, th e n therhombus is more specifi-cally called a squareThe diagonals arcperpendicular bi sectorsofeach otherEach diagonal bi sects thepair of oppos ite angl eswhose vertices arc th eendpoints ofthe diagonal4 equal s ides and 4 equalang les; every squareboth a rectangle and arhombusThe diagonals arecongruent, bi sec t eachother, arc perpe ndicul a rto each other and bisectthe int erioranglesA FThi s indicatethe re lati ons hips of quadri lateral sA=QuadrilateralsB=RhombiC=RectanglesD=SquaresE=Trape zoidsF=ParallelogramsAn isequal to hal fof its intercepted arc (the arc whichli es in the interior ofthe insc ri bedangle and whose endpoint are onthesidesoftheangle)r-... mMPNmMN If two int erceptthe same are, then th e angles arecongruent] fa is inscribed in acircle, t hen oppos ite ang les areupplemen taryAn angle insc ri bed in a el11i eircleis always a ri ght angl eAnCircles(coi/lilllled) An angle formed by a and a equal to half the difference of the itse xternal segmentlength=the productis equal to halfofthe measure interceptedarcs of the other secant and its e xternalofits intercepted arc When two chords intersect inside a segment lengthangle formed by two chords circle, the product of the segment Whe n a tangent and a secant lineintersecting inside a circle = to halfthelengths ofone chord=to the product of segment are dra wn to a c ircle frol11 thesum ofthe intercepted arcsthe segment lengthsofthe otherchord same exterior point, the square ofAn angle formed by two secants, or twoWhen two secant line segments are the length of the tangenttangents, or a secant and a tangent, thatdrawn to a circle from the same exteriorsegment= to the product o f th eintersectata pointoutsideofthecircleisendpoint, the product ofone secant andsecantand its externa lsegment lengthiUr-----------------------------------------------------------------Aa The area, A, of a two-di mens ional shape is the number ofsquare units that can be put in the region enclosed by the sidesArea is obtained through some combination ofmultiplyinghei ghts and bases, which always form 90 angles with each ot her,except in circlesIfb=8,then: A=64square units A=lrh, orA=/w IfII =4and b= 12, then: A =(4)(12),A=48 square units A=!hh ZA = 1(8)(12),A=48 squareunitsiUA=hhD.Ifh=6 and h=9, then: CA= (6)(9),A= 54sq uare units A=1h(h,+h2)If h = 9, hi= 8 andh2=12, then:A=1(9)(8+12),A = 1(9)(20),A=90 square unitsA=lrt2 A=1rr2; If r =5,then: A=n:52=(3.14)25=78.5 square units bl

C=21tr Ifr=5,then: C=(2)(3. l4)(5)=10(3. 14) = 3 1.4 units blegsa and h,then: c2=a2+h2If a right triangle has hypotenusecandV=/wlr If/ =12, w= 3 and Ir = 4,then:"o;pZ V=(12)(3)(4), V=144 cub ic units w I "OTE: TO Due IU il sfonnal . pl cn'>CD. fl .."igncu orl.;1\11 r ighl\ r escn ecl. No pan or pll hli..: ation may herc p rt K! u