2. Main Idea and New Vocabulary Key Concept: Volume of a Pyramid
Example 1: Find the Volume of a Pyramid
Example 2: Real-World Example
Key Concept: Volume of a Cone
Example 3: Find the Volume of a Cone
Key Concept: Volume of a Sphere
Example 4: Find the Volume of a Sphere
Lesson Menu

3. Find the volumes of pyramids, cones, and spheres.
Main Idea/Vocabulary

4. Key Concept

5. Find the Volume of a Pyramid
Find the volume of the pyramid. Round to the nearest tenth, if necessary.
Volume of a pyramid
B = 7 ● 3, h = 20
Simplify.
Answer: The volume is about 140 cubic centimeters.
Example 1

6. Find the volume of the pyramid
Find the volume of the pyramid. Round to the nearest tenth, if necessary.
A. 200 ft3
B. 300 ft3
C. 400 ft3
D. 600 ft3
Example 1 CYP

7. Replace V with 9 and B with 3 • 3 or 9.
AWARD The Amazing Bread Company gives a pyramid-shaped award to students who have learned how to use the food pyramid to choose from the 5 food groups. The award has a square base with sides 3 inches long. If the volume is 9 cubic inches, find the height of the award.
Volume of a pyramid
Replace V with 9 and B with 3 • 3 or 9.
9 = 3h Multiply.
Example 2

8. Answer: The height is 3 inches.
Divide each side by 3.
3 = h Simplify.
Answer: The height is 3 inches.
Example 2

9. PAPERWEIGHT A pyramid-shaped paperweight has a rectangular base with sides 8 centimeters and 11 centimeters long. If the volume is 176 cubic inches, find the height of the paperweight.
A. 2 cm
B. 4 cm
C. 6 cm
D. 8cm
Example 2 CYP

10. Key Concept 2

11. Find the Volume of a Cone
Find the volume of the cone. Round to the nearest tenth.
Since the diameter is 3 meters, the radius is 1.5 meters.
Volume of a cone
Replace r with 1.5 and h with 8.
Simplify. Use a calculator.
Answer: The volume is about 18.8 cubic meters.
Example 3

12. Find the volume of the cone. Round to the nearest tenth.
A mm3
B mm3
C mm3
D. 1,244.1 mm3
Example 3 CYP

13. Key Concept 4

14. Find the Volume of a Sphere
Find the volume of the sphere. Round to the nearest tenth.
Volume of a sphere
r3
Replace r with 7.
●  ● 73
Simplify. Use a calculator.
Answer: The volume of the sphere is about 1,436.8 cubic centimeters.
Example 4

15. Find the volume of the sphere. Round to the nearest tenth.
A ft3
B ft3
C. 2,290.2 ft3
D. 3,053.6 ft3
Example 4 CYP