1. Bell Ringer: Fractions Write the answer in simplest form. 1. 2. 3. 4. 5. 6.

2. 2 Lesson 9-4 Spheres

3. 3 A sphere is formed by revolving a circle about its diameter. In space, the set of all points that are a given distance from a given point, called the center. Definition:

4. 4 Spheres – special segments & lines Radius: A segment whose endpoints are the center of the sphere and a point on the sphere. Chord: A segment whose endpoints are on the sphere. Diameter: A chord that contains the sphere’s center. Tangent: A line that intersects the sphere in exactly one point. Radius Chord Diameter Tangent

5. 5 Surface Area & Volume of Sphere Volume (V) = Surface Area (SA) = 4 π r 2 r Example:Find the surface area and volume of the sphere. 12 cm

6. 6 Great Circle & Hemisphere Great Circle: For a given sphere, the intersection of the sphere and a plane that contains the center of the sphere. Hemisphere: One of the two parts into which a great circle separates a given sphere. Great Circle Hemisphere

7. Find the Surface area and Volume of each sphere. 7 1. 2.

8. 8 Surface Area & Volume of Hemisphere Find the surface area and volume of the following solid (Hemisphere). 10 cm

9. Homework Pg. 520 # 8- 18 9