Which solid has one curved surface and two congruent circular bases?

Which solid has one curved surface and two congruent circular bases?

• A. Cone
• B. Sphere
• C. Cylinder
• D. Prism

Answer: (C)

Think about a shape that wraps around like a tube and ends in two equal circular faces. That’s a cylinder. It has one continuous curved surface that goes all the way around, plus two flat circular bases that are the same size and parallel to each other. If you could unwrap the curved part, it would lay flat as a rectangle whose width equals the base’s circumference and whose height equals the distance between the bases. A cone has one circular base and a pointed tip, not two bases. A sphere is completely curved with no flat bases at all. A prism has flat, polygonal bases and no curved surface. So the description fits a cylinder perfectly.

Think about a shape that wraps around like a tube and ends in two equal circular faces. That’s a cylinder. It has one continuous curved surface that goes all the way around, plus two flat circular bases that are the same size and parallel to each other. If you could unwrap the curved part, it would lay flat as a rectangle whose width equals the base’s circumference and whose height equals the distance between the bases.

A cone has one circular base and a pointed tip, not two bases. A sphere is completely curved with no flat bases at all. A prism has flat, polygonal bases and no curved surface. So the description fits a cylinder perfectly.