# ∠A and ∠B are vertical angles with m∠A = x and m∠B = 5x − 80. What is m∠A?

We will use the concept of vertically opposite angles to answer this question.

## Answer: ∠A and ∠B are vertical angles with m∠A = x and m∠B = 5x − 80, m∠A = 20°

Vertically opposite angles are always equal.

**Explanation:**

Since vertically opposite angles are always equal, m∠A = m∠B.

So, now we will solve a linear equation to find the answer.

x = 5x - 80

5x - x = 80

4x = 80

x = 20