Question

The measure of two complementary angles are in the ratio 1 : 4. What are the degree measures of the two angles?

Answer 1

Since the angles are complementary, they add to 90°. So we can write the equation:
x represents the first angle, and 4x represents the second
x+4x=90
5x=90
x=18 

So the first angle is 18° and the second is 72° (18*4)

Hope this helps