12.3 Surface Area of Pyramids and Cones

1
12.3 Surface Area of Pyramids and Cones

• Assignment 16 12.3 WB Pg. 154 1 10 all

2
Example 5-1a
Find the surface area of the square pyramid.
Find the lateral area and the base area. Area of
each lateral face
There are 4 faces, so the lateral area is 4(35.6)
or 142.4 square feet.
3
Example 5-1b
Area of base
Answer The surface area of the square pyramid is
206.4 square feet.
4
Example 5-1c
Find the surface area of the square pyramid.
5
Example 5-2a
Canopies A canopy is in the shape of a square
pyramid that is 3.4 meters on each side. The
slant height is 2 meters. How much canvas is used
for the canopy?
Find the lateral area only, since there is no
bottom to the canopy. Area of each lateral face
6
Example 5-2b
One lateral face has an area of 3.4 square
meters. There are 4 lateral faces, so the
lateral area is 4(3.4) or 13.6 square meters.
Answer 13.6 square meters of canvas was used to
cover the canopy.
7
Example 5-2c
Tent A tent is in the shape of a square pyramid
that is 8 feet on each side. The slant height is
10 feet. Find the surface area of the tent.
8
Example 5-3a
Find the surface area of the cone. Round to the
nearest tenth.
Answer The surface area of the cone is about
148.4 square feet.
9
Example 5-3b
Find the surface area of the cone. Round to the
nearest tenth.