Question

The measure of an angle is nine times the measure of a supplementary angle. What ls the measure of each angle?

Answer 1

Find 2 supplementary angles.

Explanation:

Call x the angle and y its supplementary.
We get 2 equations:
x + y = pi (1)
x = 9y (2)
Replace x by 9y into the equation (1), we get:
9y + y = pi --> 10y = pi --> `y = pi/10` --> `x = (9pi)/10`