Do Now 2/22/10Do Now 2/22/10 Take out your HW from last week.Take out your HW from last week.

Text p. 285, #1-10 allText p. 285, #1-10 all

Copy HW in your planner.Copy HW in your planner.Text p. 291, #8-20 allText p. 291, #8-20 allReview “Geometry NJASK7 Prep” assignment on Review “Geometry NJASK7 Prep” assignment on

MySkillsTutor – Quiz Friday MySkillsTutor – Quiz Friday

Be ready to copy POTW #4. Be ready to copy POTW #4.

““Basic Geometry Concepts” Basic Geometry Concepts”

PointPointposition in space position in space represented by a dot. represented by a dot.

AA

ZZ

DD

KK

LL

PlaPlanenea flat surface that extends on a flat surface that extends on

forever in all directions. forever in all directions.

How many planes on this figure?How many planes on this figure?

Line segmentLine segmentpart of a line with 2 endpoints and all the points in between.

C

D

E

FDC

EF

CD

FE

LinLinee a straight path extending a straight path extending

without end in 2 directions. without end in 2 directions.

RR

TTRT

ST

RS

SS

RayRayPart of a line that beginsPart of a line that beginsat a point and extends in one at a point and extends in one direction without ending. direction without ending.

AA

KK

AAKK

BB

ABABJKJK

JJ

CongruentCongruentTwo line segments are Two line segments are congruent when they are the congruent when they are the same length. same length.

CC DD EE FF

3EF

EFCD

33

AngleAngleTwo rays that begin at the Two rays that begin at the same point. same point.

CC

DD

EEVertexVertex

SidesSides

Naming Angles The following angle can be named in three ways:

BB

CCAA

BAC ACABVertexVertex

Objective

SWBAT identify similar and congruent figures

HomeworkHomeworkText p. 286, #1-10 allText p. 286, #1-10 all

1) M, N, P, R, S 2) 3) plane Y and plane Z 4) 5) 6) 7) quadrilateral DEFG 8) 9) 10)

,,,, GFED

DGEFFGDE

GEFD

,

,,

RSMN &

NPMNRS ,,

SRRSNPMN ,,,

85; NmN

DGFGEFDE ,,,

Section 6.4 “Similar and Congruent Figures”Section 6.4 “Similar and Congruent Figures”

Similar FiguresSimilar Figures

Two figures are Two figures are SIMILAR FIGURESSIMILAR FIGURES if they have if they have the the same shapesame shape but not necessarily the same but not necessarily the same size. The symbol ~ indicates two figures are size. The symbol ~ indicates two figures are similar. similar.

Properties of similar figures:Properties of similar figures:

1). Corresponding angles are congruent1). Corresponding angles are congruent

2). Corresponding sides are proportional (equal ratios)2). Corresponding sides are proportional (equal ratios)

DA FC AA

BB

CC

DD

EE

FF

Corresponding angles –Corresponding angles – matched angles of two figuresmatched angles of two figures

EB

When 2 angles When 2 angles have the same have the same

measure, they are measure, they are marked with the marked with the same symbol.same symbol.

DEFABC ~

DE

AB

DF

AC

AA

BB

CC

DD

EE

FF

Corresponding sides –Corresponding sides –

matched sides of two figuresmatched sides of two figures

EF

BC

DEFABC ~

Given ABC ~ XYZ, name the corresponding angles and corresponding sides.

C

A

B

Y

Z

X

YC

ZB

XA

,

,SidesAngles

YZandCB

XZandAC

XYandAB

,

,

C

A

B

1616

2828

3232 F

D

E

2020

3535

4040

FE

CB

DE

AB

DF

AC

35

28

40

32

20

16

Given ABC ~ DEF, find the ratio of the lengths of the corresponding sides.

5

4

35

285

4

40

325

4

20

16

The ratio of thelengths of the corresponding sides is 4/5.

C

A

B

44

33

55 F

D

E

66

4.54.5

7.57.5

FE

CB

DE

AB

DF

AC

5.4

3

5.7

5

6

4

Given ABC ~ DEF, find the ratio of the lengths of the corresponding sides.

3

2

6

43

2

45

30

5.4

33

2

75

50

5.7

5

The ratio of thelengths of the corresponding sides is 2/3.

Congruent FiguresCongruent Figures

Two figures are Two figures are CONGRUENT FIGURESCONGRUENT FIGURES if they if they have the have the same shapesame shape AND the AND the same sizesame size. .

Properties of congruent figures:Properties of congruent figures:

1). Corresponding angles are congruent1). Corresponding angles are congruent

2). Corresponding sides are congruent2). Corresponding sides are congruent

Given , find the indicated measure.

C

A

B

2020

4545

Y

ZX

1515

4545

XYZABC

YX

ZmCB

Ym

3535°° 1515

9090°°

3535°°

Am 5555°°

HomeworkText p. 291, #8-20 allText p. 291, #8-20 all