Answer:
The measure of the third angle is a 90 degrees
Explanation:
Let
A and B ----> two complementary angles in a triangle
C ---> the measure of the third angle in a triangle
we know that
If two angles are complementary, then their sum is equal to 90 degrees
so
---> equation A
Remember that
The sum of the interior angles in any triangle must be equal to 180 degrees
so
----> equation B
substitute equation A in equation B

solve for C
subtract 90 degrees both sides


therefore
we have a right triangle