Which shape best describes the object generated when half circle is rotated about the axis?

solid sphere

solid cylinder

hollow sphere

hollow cylinder

Hollow sphere

Step-by-step explanation:

When a half circle is rotated about the axis, it form a 3-D ring around the axis such that the region inside the ring will be empty because its half of a circle.

Therefore, it will create a hollow sphere or ball when  half circle is rotated about the axis

Hence, Hollow sphere is the best shape which describes the object generated when half circle is rotated about the axis.

70

step-by-step explanation:

2*5=10

4*15=60

60+10=

70