#### Answer

24 inches

#### Work Step by Step

The apothem of a regular polygon forms a right triangle with half of a side and a radius. Since the apothem has a length of 3 and half of a side has a length of 3, it is a 45 45 90 triangle. The central angle of the polygon is equal to twice the measure of the angle between the apothem and the radius which in this case is 45 degrees. Therefore the central angle has a measure of 90 degrees. A regular polygon with right central angles is a square.
P=4s
P=4(6)
P=24