Major objective of this lecture is to present on Length and Perimeter. The Perimeter of a shape is the distance around the shape. It is the sum of the lengths of the sides of the shape. Find the perimeter of a triangle with sides measuring 10 inches, 14 inches and 15 inches. A rectangle has a length of 12 centimeters and a width of 4 centimeters. Find the perimeter. Find the perimeter of a regular hexagon with each side measuring 8 meters.