1. Surface Area of Pyramids
Lesson 9.2
7.G.6: Solve real-world and mathematical problems involving area, volume, and surface area of two- and three-dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms.

2. Pyramids Pyramids are named from their base shape
Most pyramids we’ve seen are square pyramids but there are plenty of others as well…

3. Parts of a pyramid
A regular pyramid is a pyramid whose base is a regular polygon (all sides equal). The lateral faces are triangles.
The height of each triangle is the slant height of the pyramid.

4. Surface Areas of Pyramids and Cones
Regular Pyramid
The slant height of a pyramid or cone is measured along its lateral surface.
Right cone
The base of a regular pyramid is a regular polygon, and the lateral faces are all congruent.
In a right cone, a line perpendicular to the base through the vertex passes through the center of the base.

5. Another look Surface Area of Pyramid =
Area of Base + Areas of Lateral Faces

7. Example 1A: Finding Surface Area using a net

8. Example 1B: Find the Surface Area of a Pyramid
Find the surface area of the figure.
SA = B + 1/2 Pl
= (2.4 • 2.4) (9.6)(3) 1 2
= ft2

9. You Try!
What is the surface area of a square pyramid with a base side length of 9 cm and a slant height of 7 cm? (Draw a picture, then solve)
207 cm2

10. Example 2: Finding Surface Area of a Triangular Pyramid

11. Surface Area of a Composite Solid
Composite Solid: A figure that consists of two or more geometric shapes

12. Surface Area of a Composite Solid
When finding the surface area of a composite solid, remember that surface area is only the area of the SURFACES (some parts of figures get covered)

13. Example 3 – Find the surface area of a composite figure
283.5 cm2

14. Example 4: Real-Life Application

15. 17 bundles Example 4 extension
One bundle of shingles covers 32 square feet. How many bundles should you buy to cover the roof?
17 bundles

16. You Try!
105.6 ft2

17. Additional Example: Find the Surface Area of a Cone
Find the surface area of each figure to the nearest tenth. Use 3.14 for p.
SA = pr2 + prl
18 ft
= p(72) + p(7)(18)
7 ft
= 175p  ft2

18. Homework 
p.366 #1-3, 8-16 even, 17-20