Kate wants to build a fence around her yard. the width of the yard is one-third the length. the perimeter of the yard is 80 feet. what is the length and width of her yard?

P = 2(L + W)
P = 80
W = 1/3L

80 = 2(L + 1/3L)
80 = 2(3/3L + 1/3L)
80 = 2(4/3L)
80 = 8/3L
80 * 3/8 = L
240/8 = L
30 = L length (L) is 30 ft

W = 1/3L
W = 1/3(30)
W = 30/3
W = 10 <== width (W) = 10 ft

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