noun, noun which may take the genitive case particle 'no'
Refers to a five-sided polygon. Used in geometry and everyday contexts.
五角形のテーブルを買った。
I bought a pentagon-shaped table.
この図形は五角形です。
This shape is a pentagon.
pentagon
pentagonal prism
pentagonal pyramid
From 五 (five) + 角 (angle, corner). The reading ごかく is the on'yomi of both characters.