Explanation

A pentagon is a five-sided polygon, and the included angle of a pentagon is the angle formed by two consecutive sides of a pentagon. The included angle of a regular pentagon is defined as the angle between two consecutive sides of the pentagon, and it is the same for all sides of a regular pentagon.

The formula to find the included angle of a regular pentagon is: Included angle = (180 - 360/n) degrees

where "n" represents the number of sides of the polygon. In the case of a pentagon, n=5.

So the included angle of a regular pentagon: (180 - 360/5) = (180 - 72) = 108 degrees.

A regular pentagon has five angles that are equal to 108 degrees each and five sides that are congruent.