1. 6.9 Surface Area and Volume of Spheres Performance Exam: TOMORROW *You will get the review after notes*

2. Vocabulary A sphere is the set of all points in space equidistant from a given point. –This point is called the center of the sphere. A radius of a sphere is a segment from the center to a point on the sphere. A chord of a sphere is a segment whose endpoints are on the sphere. A diameter of a sphere is a chord that contains the center.

3. Vocabulary A great circle is the intersection of a sphere and a plane passing through the center of the sphere. –The circumference of a great circle is the circumference of the sphere.

4. Vocabulary A hemisphere is half of a sphere, formed when a great circle separates a sphere into two congruent halves. Great Circle

5. Vocabulary Surface Area of a Sphere S = 4πr 2 Volume of a Sphere V = 4/3πr 3

6. Example 1: Find the surface area of the sphere.

7. Example 2: The circumference of a sphere is 12π feet. Find the surface area of the sphere. –They give us the circumference, so we can find the radius. –Once we have the radius we can find surface area. C = 2πr

8. You Try: If the surface area of a sphere is 324π cm 2. Find the radius of the sphere.

9. Example 3: Find the volume of the sphere.

10. Classwork/Homework: Review the possible topics for the Performance Exam tomorrow!