Which term describes a three-dimensional figure with a flat base that tapers to a single apex?

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

Answer: (D)

A cone is a three-dimensional figure that has a flat base and narrows to a single point called the apex. The base is circular, and every line from the edge of the base meets at that apex, giving a smooth taper from base to point. While a pyramid also ends at an apex, its base is a polygon and its sides are flat triangles, not a single curved surface. A cylinder features two flat bases and a curved side with no apex, and a sphere has no apex or flat base at all. So the term that best matches a flat base tapering to one apex is cone.