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