# Sphere

#### Spherical Surface

A spherical surface is the surface generated by rotating a circle about its diameter.

#### Sphere

A sphere is the region of the space that is inside a spherical surface.

### Center

The **center** is the interior point that is equidistant to all points on the surface of the sphere.

### Radius

The **distance** from the center to any point on the surface of the sphere.

### Diameter

The **diameter** is the distance from one point through the center to another point.

### Surface Area of a Sphere

### Volume of a Sphere

#### Examples

A cube with an edge of 20 cm is filled with water. Would this amount of water fit in a sphere with a 20 cm radius?

Calculate the area and the volume of a sphere inscribed in a cylinder with a height of 2 m.

Calculate the area of the circle resulting from cutting a sphere of 35 cm radius by a plane whose distance from the center of the sphere is 21 cm.