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,
![\begin{gathered} a+\theta=180^(\circ) \\ a+28\degree=180^(\circ) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/chq1tmkdqaf644mm186fiofywy2cvgub0c.png)
Now, solve the equation for a.
![\begin{gathered} a=180^(\circ)-28\degree \\ a=152\degree \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/e7f0w8d1oq9uedv2ac9gtoafx3kh1039hg.png)
Therefore, the measure of the supplement of the angle measure 28 degrees is 152°.