lesson 8.2b lateral and surface area of pyramids and cones standards: m.3.g.2 m.3.g.3

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Lesson 8.2B Lesson 8.2B Lateral and Surface Area of Pyramids and Cones Standards: M.3.G.2 M.3.G.3

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Lesson 8.2BLesson 8.2BLateral and Surface Area of

Pyramids and ConesStandards: M.3.G.2

M.3.G.3

ReviewReview

Surface Area:The sum of the areas of the faces

of a polyhedron

Lateral Area:The sum of the areas of the faces

of a polyhedron except for the base

Lateral Area - PyramidsLateral Area - Pyramids

Lateral Area = ½ P l

P: Perimeter of the base

l: slant height

ExampleExample

Find the lateral area of the right square pyramid. Round your answer to the nearest whole number:

18'

24'

Surface Area - PyramidsSurface Area - Pyramids

Surface Area = LA + B

LA: Lateral Area

B: Area of the Base

ExampleExample

Find the surface area of the right square pyramid. Round your answer to the nearest whole number:

10'

12'

Now You Try…Now You Try…

Find the lateral area and the surface area of the regular triangular pyramid. Round your answer to the nearest whole number:

13”

10”

Lateral Area - ConesLateral Area - Cones

Lateral Area = π r l

r: radius of the base

l: slant height

ExampleExample

Find the lateral area of the cone. Round your answer to the nearest whole number.

6"

12"

Surface Area - ConesSurface Area - Cones

Surface Area = π r l + π r2

r: radius of the base

l : slant height

ExampleExample

Find the surface area of the cone. Round your answer to the nearest whole number.

8"

15"

Now You Try…Now You Try…

Find the lateral area and the surface area of the cone. Round your answer to the nearest whole number.

11"

31"

Real Life Application Real Life Application ProblemsProblemsExample:The framework for a decorative

trellis to support a grapevine is in the shape of a square pyramid. If the height is 6 meters and the width of the base is 2 meters, what amount of netting is needed to protect the grapes from the birds? Round your answer to the nearest whole number.

ExampleExampleThe framework for a decorative trellis to support a

grapevine is in the shape of a square pyramid. If the height is 6 meters and the width of the base is 2 meters, what amount of netting is needed to protect the grapes from the birds? Round your answer to the nearest whole number. 6 m

2 m

Now You Try…Now You Try…

A toy company plans to market a square pyramid-shaped space station component for its line of Galaxy Generation figures. The space station will need to be coated all over the outside with a reflective paint. How many square inches will need to be painted on each item? Round your answer to the nearest whole number.

Now You Try…Now You Try…A toy company plans to market a square pyramid-

shaped space station component for its line of Galaxy Generation figures. The space station will need to be coated all over the outside with a reflective paint. How many square inches will need to be painted on each item? Round your answer to the nearest whole number.

8”

16”