1. 6.9
Surface Area
of Spheres

2. Radius of a Sphere r

3. If you cut a sphere right down the middle you would create two congruent halves called HEMISPHERES.
You can think of the globe. The equator cuts the earth into the northern and southern hemisphere.

4. A circle!!! This is called the GREAT CIRCLE of the sphere.
Look at the cross section formed when you cut a sphere in half.
What shape is it?
A circle!!! This is called the GREAT CIRCLE of the sphere.

5. Surface Area of a Sphere

6. Surface Area of a Sphere
(round to the nearest hundredths)
8 in

7. Surface Area of a Sphere
(round to the nearest hundredths)
10 cm

8. The circumference of a great circle of a sphere is 25 inches
The circumference of a great circle of a sphere is 25 inches. Find the surface area of the sphere. (Round to the nearest tenths.)
25 in

9. Surface Area of a Sphere
A spherical balloon has an initial radius of 5 in. When more air is added, the radius becomes 10 in. Explain how the S.A. changes as the radius changes.
5 in
10 in

10. Volume of Spheres

11. Volume of a Sphere

12. Volume of a Sphere
(round to the nearest hundredths)
2 cm

13. Volume of a Sphere
10 cm

14. Volume of a Sphere
A spherical balloon has an initial radius of 5 in. When more air is added, the radius becomes 10 in. Explain how the volume changes as the radius changes.
5 in
10 in

15. Homework
pp #s 1-18; 23