If two angles are supplementary and one of them is 30°, what is the measurement of the second angle?

 If the sum of two angles is 180° then they are called supplementary angles.

Answer: If two angles are supplementary and one of them is 30°, the measurement of the second angle is 150°.

Let’s solve it step by step.

Explanation: 

Given: One of the angles = 30º

Let the other angle be 'a'.

We know that the sum of supplementary angles is equal to 180°.

Thus,

a + 30° = 180° [sum of supplementary angles is 180°]

⇒ a = 180° - 30°

⇒ a = 150°

Thus, the other angle is 150°

We can also calculate the supplementary angles by using a supplementary angle calculator.

Therefore, the measurement of the second angle is 150°.