SurfaceAreaofPyramids Name:Pre-Algebra Date:Chapter10–Lessons4and6

Pre-Algebra Date:Chapter10–Lessons4and6

Moreresourcescanbefoundonourclasswebsite:www.elliottsttims.weebly.com/resources

TriangularPyramids

Thisisatriangularpyramid.Thebaseisatriangle,anditcomestoonepointatthetop.

Thisyearallofthelateralfacesofapyramidwillbecongruent,isoscelestriangles.ThebaseswillberegularpolygonsFindthesurfaceareaofthistriangularpyramid:

Draweachofitsfacesbelow,andfindtheareaofeach:Base(base8cm,height7cm;Area=(1/2)8x7=28squareunits)

3lateralfaces(base8cm,height18cm;Area=(1/2)8x18=72squareunits)

SurfaceAreaofPyramids Name:Pre-Algebra Date:Chapter10–Lessons4and6

Pre-Algebra Date:Chapter10–Lessons4and6

Moreresourcescanbefoundonourclasswebsite:www.elliottsttims.weebly.com/resources

SurfaceArea=sumofareasofeachfaceSA=72+72+72+28SA=244squareunits

SquarePyramids ThisisaFAMOUSsquarepyramid.It’sasquarepyramidbecauseitsbaseisasquare!This is the entrance to the Louvre museum in Paris. The bottom is open, so people can go down the elevator into the lobby. How much glass did it take to create this work of art?

4congruenttriangularlateralfaces:

𝐴! =12 𝑏ℎ

𝐴! =12 (35)(28)

𝐴! = (14)(35)𝐴! = 490 𝑚!

Squarebase:It’sopen,sothere’snoglassonthebase!SurfaceArea:

𝑆𝐴 = 4 𝑡𝑟𝑖𝑎𝑛𝑔𝑙𝑒𝑠𝑆𝐴 = 4 (490)𝑆𝐴 = 1,960 𝑚!