A) width = length * 3
B) width * length = 36
Substituting equation A) into B)
length * 3 * length = 36
3 * length^2 -36 = 0
length ^2 -12 = 0
length = 3.4641
width = 3 * 3.4641 =
10.3923
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Double-check
area = 3.4641 * 10.3923
area = 36