$\"\"$

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Given that, $\"\"$ .

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Observe the figure :

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In $\"\"$ , the value of $\"\"$ and $\"\"$ .

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Since $\"\"$ is the one of the right angle traingle, apply pythagorean theorem: $\"\"$ .

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Substitute $\"\"$ and $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Since $\"\"$ , apply similarity rule of the two right angle traingle : $\"\"$ .

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Substitute $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$ in the above formula.

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$\"\"$

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$\"\"$ .

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Option (C) is the correct choice.

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$\"\"$

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Option (C) is the correct choice.