1. Lesson 12-4 Spheres (page 497)
Essential Question
How do you calculate the area and volume of a sphere?

2. Spheres
Set your goals high …
reach for the impossible!

6. Sphere
A sphere is the set of all points in space that are a given distance from a given point.

7. example:
sphere X X

8. example:
sphere X X r

9. The area of a sphere equals 4π times the square of the radius.
Theorem 12-9
The area of a sphere equals 4π times the square of the radius.

10. The volume of a sphere equals 4/3 π times the cube of the radius.
Theorem 12-10
The volume of a sphere equals 4/3 π times the cube of the radius.

11. Example #1 Find the area and volume of a sphere with radius 5 cm.

12. Example #2 The volume of a sphere is 972 π ft3. Find its area.

18. How do you calculate the area and volume of a sphere?
Assignment
Written Exercises on page 500
GRADED: 9, 11, 15, 19
BONUS #16
Identifying the 3-D models BONUS
Name the two (2) wooden models.
Name the clear plastic model.
Name the metal model.
How do you calculate the area and volume of a sphere?

19. Chapter 12: Areas and Volumes of Solids is due on ________________.
Take Home Test on
Chapter 12: Areas and Volumes of Solids
is due on ________________.
Why is it important to calculate surface area and volume of three dimensional solids?