Question 983915
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A=known dimension=50ft; B=unknown dimension; C=diagonal=130ft
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{{{A^2+B^2=C^2}}}
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{{{B^2=C^2-A^2}}}
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{{{B=sqrt(C^2-A^2)}}} 
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{{{B=sqrt((130ft)^2-(50ft)^2)}}}
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{{{B=sqrt(16900ft^2-2500ft^2)}}}
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{{{B=sqrt(14400ft^2)}}}
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{{{B=120ft}}}
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ANSWER: The unknown dimension is 120 feet.