# The ratio of two supplementary angles is 2:7. What's the measure of the smaller angle?

Apr 4, 2018

color(green)("Measure of the smaller angle " = 40 ^@
Given : $2 x + 7 x = {180}^{\circ} , \text{ as the two angles are supplementary}$
$9 x = 180 , \text{ or } x = {\cancel{180}}^{\textcolor{red}{20}} / \cancel{9} = {20}^{\circ}$
$\text{Smaller angle } = 2 x = 2 \cdot 20 = {40}^{\circ}$