Given:
The angle measure, θ=28°.
Two angles are said to be supplementary angles if the sum of the angles is equal to 180 degrees.
Let a be the measure of the supplement of θ=28°. Then, we can write,
[tex]\begin{gathered} a+\theta=180^{\circ} \\ a+28\degree=180^{\circ} \end{gathered}[/tex]Now, solve the equation for a.
[tex]\begin{gathered} a=180^{\circ}-28\degree \\ a=152\degree \end{gathered}[/tex]Therefore, the measure of the supplement of the angle measure 28 degrees is 152°.
