When would you use the total 180° to find the measure of an angle?

In any instance.

Step-by-step explanation:

A triangle has three sides, and the angle measures for all three angles will add up to a total of 180°.

∠A + ∠B + ∠C = 180°

Example:

Find ∠C if ∠A = 60° and ∠B = 50°.

60° + 50° + ∠C = 180°

∠C = 70°