Algebra question on finding length and width while knowing perimeter

Question

July used 36 feet of fencing to enclose a rectangular garden and put a divider between them. The width of the garden is one third of the total length. Find the dimensions of the garden and area.

Answer 1

Draw a giagram.

If width is w, then length is 3w.

Total length of fence is 3w + 3w + w + w + w (extra w because of divider)

So 9w = 36

w = 4

3w = 12

So

garden is 12 x 4 ft, with area 12 x 4 = 48 ft²