SOLUTION: How do you find the measure of interior angles of a triangle when you have 1 int. angle measuring 25 deg.and 1 ext. angle measuring 135 deg.? (scalene triangle)

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Question 1061975: How do you find the measure of interior angles of a triangle when you have 1 int. angle measuring 25 deg.and 1 ext. angle measuring 135 deg.? (scalene triangle)
Answer by math_helper(2461) About Me  (Show Source):
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An important property of interior and exterior angles is that they add to 180 degrees.
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So if one angle is 25 degrees, the exterior angle of 135 must be at one of the other two vertices (because this 25 degree angle would have 180-25 = 155 degree exterior angle). The vertex with 135 degree exterior angle has an interior angle of 180-135 = 45 degrees.
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Now you have two of the three angles. Here is the last fact for you to find the 3rd angle: the three interior angles of a triangle add to 180 degrees. We know one is 25 and the other is 45, so the last one can be found.