pentagon

A pentagonal building has 5 major sides to its dominant footprint. The five sides do not have to be equal in length, and may include some irregularities such as notches. Some chamfering or rounding of the corners are possible as long as the shape gives the general impression of a pentagon.

The dominant footprint gives the impression of five sides. Equal side lengths and mathematically exact corners are not required.

A slight chamfer can remain a corner detail rather than becoming another principal side. The distinction from a hexagon is the overall five-sided form, not a count of every short segment around a notched facade.