Question

using the piling method, which of the following can be constructed from discs alone?
check all that apply.
a. cone (including the vertex)
b. cone (not including the vertex)
c. square
d. prism
e. cube
f. cylinder

Explanation:

• A cone including the vertex cannot be made from discs alone, as the vertex is a single point (not a disc).
• A cone excluding the vertex can be constructed by piling discs of decreasing radius (approaching 0 but never reaching it).
• A square is a 2D shape, so it cannot be formed by piling 3D discs.
• A prism has rectangular cross-sections, not circular discs, so it cannot be formed this way.
• A cube has square cross-sections, not circular discs, so it cannot be formed this way.
• A cylinder can be constructed by piling identical circular discs of the same radius.

Answer:

B. Cone (not including the vertex)
F. Cylinder