Let a equal measure of a angle a. The equation 360゚= a + 90゚+ 135゚+ 75゚ represents the sum of the angles in the quadrilateral. Find the missing angle measure by solving the equation.

Answer:
A = 60°
Step-by-step explanation:
First to find the missing angle you add the three known angles,
90 + 135 + 75 = 300
Then, you subtract, 360 - 300 = 60