Answer:
![x=45°](https://img.qammunity.org/2023/formulas/mathematics/college/6oobytck3xp3f9oeue0xfq18yua356ny9b.png)
Explanation:
Given that supplementary of an angle is 3 times its complementary angle. Let x be the angle measured.
Therefore, the supplementary angle of x will be 180-x and the complementary angle of x will be (90-x). If the supplementary angle is 3 times the complementary angle:
![\begin{gathered} 180-x=3(90-x) \\ 180-x=270-3x \\ 3x-x=270-180 \\ 2x=90 \\ x=45° \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/9pam4yakzhzktlodz6369r08q0f0cuvmo1.png)