$\"\"$

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The given angle measures are $\"\"$ .

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$\"\"$ (Angle sum theorem)

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$\"\"$ (Substitute angle values)

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$\"\"$ (Simplify)

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$\"\"$ (Subtract 72 from each side)

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$\"\"$ (Divide each side by 9) $\"\"$

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Use $\"\"$ to determine the measures of the angles

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$\"\"$ (Given)

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

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$\"\"$ (Simplify) $\"\"$

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$\"\"$ (Given)

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

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$\"\"$ (Simplify) $\"\"$

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$\"\"$ (Given)

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

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$\"\"$ (Simplify) $\"\"$

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The value of n is 12 and the measures of angles are 56, 61, and 63.