$\"\"$

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Observe the figure:

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The sides of the triangle are $\"\"$ and $\"\"$ .

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Consider $\"\"$ and $\"\"$ .

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Find $\"\"$ .

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$\"\"$ (Pythagorean theorem)

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$\"\"$ (Substitute $\"\"$ and $\"\"$ )

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$\"\"$ (Evaluate powers $\"\"$ and $\"\"$ )

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$\"\"$ (Subtract $\"\"$ from each side)

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$\"\"$ (Apply additive inverse prpperty: $\"\"$ )

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$\"\"$ (Subtract: $\"\"$ )

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$\"\"$ (Take the square root of each side)

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$\"\"$ (Cancel square and root)

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$\"\"$ (Substitute: $\"\"$ )

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Length can not be measure in negative values.

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Therefore, the missing measure $\"\"$ .

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$\"\"$

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Find the trigonometric ratios for angle $\"\"$ : \ \

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Formulas for angles of sine, cosine and tangent:

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$\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$ (Substitute $\"\"$ and $\"\"$ )

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$\"\"$ (Substitute $\"\"$ and $\"\"$ )

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$\"\"$ (Substitute $\"\"$ and $\"\"$ )

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$\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ , $\"\"$ and $\"\"$ .