a polyhedren with one pentagonal base is a
A)pentagon
b)cube
c)pentagonal pyramid
D)prism
To determine the answer, we need to understand the characteristics of each option.
A) Pentagon: A polygon with five sides. It doesn't match the description of having a pentagonal base and being a polyhedron since it would only have one face.
B) Cube: A polyhedron with six square faces. It doesn't match the description of having a pentagonal base.
C) Pentagonal pyramid: A polyhedron with a pentagonal base and triangular faces extending from each side of the base to the apex. This matches the description given in the question.
D) Prism: A polyhedron with two parallel congruent polygonal faces called bases and rectangular faces connecting the corresponding sides of the bases. It doesn't match the description of having a pentagonal base.
Therefore, the correct answer is C) Pentagonal pyramid. It is the only option that has a pentagonal base as described.