noun
pentagonal prism
A solid geometric figure with two parallel pentagonal bases and rectangular lateral faces.
五角柱の体積を計算する。
Calculate the volume of a pentagonal prism.
角柱 is the general term for a prism; 五角柱 specifies a pentagonal base.
Compound of 五 (go, 'five'), 角 (kaku, 'angle'), and 柱 (chū, 'pillar, prism').