Question

the figure formed by the intersection of a solid with a plane parallel to the base of the solid is congruent to the base if the solid is a
a) right cone.
b) frustum of a cone.
c) rectangular pyramid.
d) right cylinder.

Explanation:

• For a right cone, the intersection of a plane parallel to the base is a circle similar to the base but not congruent (since the radius changes as the plane moves up the cone).
• For a frustum of a cone, it is already a part of a cone with two parallel - circular bases of different sizes.
• For a rectangular pyramid, the intersection of a plane parallel to the base is a rectangle similar to the base but not congruent (as the sides get smaller as the plane moves up the pyramid).
• For a right cylinder, since the lateral surface is perpendicular to the bases, when a plane is parallel to the base, the intersection is a congruent copy of the base.

Answer:

D. right cylinder.