**Geometry 12.6 Surface Area and Volume of Sph**eres

**Sphere - **is the locus of points in space that are a given distance from a point.

**Chord of a sphere** - is a segment whose endpoints are on the Sphere.

**Diameter of a sphere** - is a chord that contains the center.

**Radius of a sphere** - is a segment that goes from the center of the sphere to an endpoint on the sphere. It is 1/2 the diameter in measure.

**Surface Area of a sphere** = 4 (*pi*) r^{2}

**Volume of a sphere** - (4/3) (*pi*) r^{3}

**Great Circle of a sphere** - if a plane intersects a sphere, the intersection is either a single point or a circle.

If the plane contains the center of the sphere, then the intersection is a Great Circle of the Sphere.

Every great circle of a sphere separates a sphere into 2 congruent halves called **hemispheres**

Homework: worksheet 12.6 B