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Define x :
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Let the width be x.
Width = x
Length = 4x
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Find x :
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Perimeter = 30 ft
2 (x + 4x) = 30
2(5x) = 30
10x = 30
x = 30 ÷ 10
x = 3
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Find Length and Width :
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Width = x = 3
Length = 4x = 4(3) = 12
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Find Area :
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Area = 3 x 12 = 36 ft²
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Answer : Area = 36 ft²
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