Respuesta :

1. By definition, the sum of the Suplementary angles is 180° and the sum of the Complementary angles is 90°. Keeping this on mind, you have:

 90-x (The complement of the angle)
 180-x (The sumplement of the angle)

 "x" is the angle that you want to calculate.

 2. Then, you have:

 3(90-x)+30=180-x
 (270-3x)+30=180-x
 300-3x=180-x
 300-180=-x+3x
 120=2x
 120/2=x
 x=60°

 What is the measure of the angle?
 

 The answer is: The measure of the angle is 60°.