Width = W
Length = 2 times the width plus 3 feet = 2W + 3
Area of triangle A = L * W
A = W (2W + 3)
20 = 2W^2 + 3W
2W^2 + 3W - 20 = 0
(W + 4) (2W - 5) = 0
W + 4 = 0; W = - 4 (width cannot be negative, excluded)
2W - 5 = 0
2W = 5
W = 2.5
L = 2W + 3 = 2(2.5) + 3 = 8
Answer:
Width = 2.5 feet and Length = 8 feet
Hope it helps.