The answer: 59° .
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Explanation:
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a + b + c = 180 .
(in which, "a" , "b", and "c" represent the measurements (in degrees" of each of the THREE (3) angles in a triangle; which always add up to "180 degrees");
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Given "a = 65 degrees"; "b = 56 degrees"; Find "c" (the measurement of the "unknown" angle.).
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a + b + c = 180 ;
65 + 56 + c = 180 ; Solve for "c" .
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180 - (65 + 56) = c ;
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Note: 65 + 56 = 121 ;
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So: 180 - (65 + 56) = 180 - 121= 59 = c ; ↔ c = 59 .
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The answer: 59° .
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