Question

which three - dimensional object is formed when the shape is rotated about the axis as shown? sphere cone hemisphere cylinder

Explanation:

Step1: Recall rotation of 2 - D shapes

When a semicircle is rotated about its diameter (the axis in the given figure), every point on the semicircle moves in a circular path.

Step2: Analyze the resulting 3 - D shape

A sphere is a three - dimensional object where every point on its surface is equidistant from the center. When a semicircle is rotated about its diameter, the set of all points traced out forms a sphere. A cone is formed by rotating a right - triangle about one of its legs. A hemisphere is half of a sphere. A cylinder is formed by rotating a rectangle about one of its sides.

Answer:

sphere