Section 12-4 Spheres

Recall… Set of all points in space at a given distance from a given point. Sphere:

Great circle The intersection of a plane and a sphere so that the center of a sphere is included

hemisphere Two congruent halves of a sphere separated by a great circle.

Theorem 12-9 The area of a sphere equals times the square of the radius.

Theorem The volume of a sphere equals times the cube of the radius.

True or False 1.Every plane that intersects a sphere is a great circle. 2.The Eastern Hemisphere of Earth is congruent to the Western Hemisphere of Earth. True False

True or False 3.The diameter of a sphere is congruent to the diameter of its great circle. True