Answer: The interior angles are 38, 52, 90
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Explanation:
The exterior angle of 142 leads to an interior angle of 180-142 = 38. The adjacent interior/exterior pair of angles always add to 180. So 38+142 = 180. These two angles are supplementary, which is another way of saying they form a straight line.
Since 38 is one of the acute interior angles, the other acute interior angle is 90-38 = 52. The rule is that the acute interior angles of any right triangle always add to 90 degrees (i.e. the angles are complementary).
Lastly, the remaining interior angle is the 90 degree angle itself. All right triangles have exactly one angle that is 90 degrees. The term "right angle" is often used in place of "90 degree angle".
