Since the two angles are supplementary, and has a ratio of 1:3, we can say algebraically that
[tex]x+3x=180\degree[/tex]Let x be the measure of angle with a ratio of 1
3x be the measure of angle with a ratio of 3
Solve and we get
[tex]\begin{gathered} x+3x=180\degree \\ 4x=180\degree \\ \frac{4x}{4}=\frac{180\degree}{4} \\ x=45\degree \end{gathered}[/tex]Therefore, we have the following
x = 45° (measure of the first angle)
3x = 3(45°) = 135° (measure of the second angle)