Hi there!
The sum of complementary angles is equal to 90°.
So the ratio given is 24 : 36.
You can simplify this to 2 : 3 by dividing by 12.
2x + 3x = 90
5x = 90
x = 18
Multiply 2 to 18
18 × 2 =36
Multiply 3 to 18
18 × 3 = 54
36 + 54 = 90
So your answer is 36°.
Hope this helped! :)