The perimeter of a rectangle is 2(L x W), so if you have length of 29, double that equals 58. (2L). Perimeter of 80 - 58 = 22 (2W), so a width of greater than 11 (2W/2) would make the perimeter greater than 80. For example, L = 29, W = 12. 2(29 + 12) = 2( 41) = 82.
