Ben is planning to fence his rectangular garden the area of the garden is 50 square feet and the length of the garden is twice the width how many feet of fencing will he need

Let L = Length, and W = Width. We are given the fact that L = 2W, and also know that the area = L x W = 50 square feet. So, by substitution: 2W x W = 50 sq ft, or 2W^2 = 50 sq ft, so W = sq rt (50/2) = 5 ft. Now, L = 2W = 2(5) = 10 ft. The perimeter of the fence is given by: 2L + 2W = 2(10 ft) + 2(5 ft) =20 ft + 10 ft = 30 ft. So, Ben needs 30 ft of fencing.