Hi, Periemter is 2*L + 2*W Let x represent the width. Then the length will be 5x 2*5x + 2x = 156in solve for x 10x + 2x = 156 12x = 156 x = 13in is the width 5x = 65in is the length checking our answer 2*13in + 2*65in = 156in