A shape that has 5 sides is called a pentagon. In geometry, a pentagon is any five-sided polygon. The sum of the internal angles in a simple pentagon is 540 degrees.
Pentagons can be regular or irregular. A regular pentagon has all sides of equal length and all interior angles equal, each measuring 108 degrees. An irregular pentagon has sides and angles that are not all the same.
Pentagons are commonly seen in everyday life, such as in the design of home plate in baseball or the shape of some signs and logos.