The measure of an angle is 167.4º. What is the measure of its supplementary angle?

12.6°

Step-by-step explanation:

Two Angles are Supplementary when they add up to 180°.

Let x - sought angle measure.

The equation:

x + 167.4° = 180° subtract 167.4° from both sides

x + 167.4° - 167.4° = 180° - 167.4°

x = 12.6°