You can easily solve it MENTALLY by noticing that 154 = 11*14 is the decomposition of the number 154 into the product of two numbers, whose difference is 3 = 14 - 11. Alternatively, you can solve a quadratic equation x*(x+3) = 154, where x is the unknown width. Answer. The dimensions are 11 ft by 14 ft and the perimeter is 11+14+11+14 = 50 ft.