The perimeter of ANY polygon, regardless of the number of sides, is the sum of the measures of the sides. If you have a regular polygon, that is to say the measures of all the sides are equal, then the perimeter is the measure of one of the sides multiplied by the number of sides. For example, an equilateral triangle with side length measure of 2 would have a perimeter of 3 times 2 = 6, whereas a 3-4-5 right triangle would have a perimeter of 3 + 4 + 5 = 12.
