Two angles of a triangle measure 75° and 60°. What will be the measure of its third angle?

From the question we have:

The measures of two angles of a triangle are 75° and 60°.

Sum of the two angles = 75° + 60° = 135°

From the properties of a triangle, we know that the sum of all three angles of the triangle = 180°

Therefore, the measure of the third angle = 180° - 135° = 45°