Question

A plane intersects a prism to form a cross section that is a polygon with five sides. What is the minimum number of sides that the polygon at the base of the prism must have?

Answer 1

My instinct is to say 4. Obviously, 5 would work if you just slice across the prism, and there's no way you can have a prism with a 2-sided base. So if it's anything less than 5, it must be either 3 or 4.

Drawing pictures, I couldn't come up with a 5-sided corss-section from a triangular prism (but that doesn't mean it's not possible...i might have just not seen how).

I can get a rectanular prism to have a 5-sided cross section if you cut near (but not at) one corner of the base and then exit along the opposite edge.

Best I can do...

Answer 2

thanks I got 4 to

Answer 3

thank you i got 4 too.