The measure of angle A is 30°
Step-by-step explanation:
Let us revise the meaning of vertical angles
1. Vertical Angles are the angles opposite each other when two
lines intersect
2. vertical angles are congruent angles
∵ ∠A and ∠B are vertical angles
- Vertical angles are congruent
∴ ∠A ≅ ∠B
∴ m∠A = m∠B
∵ m∠A = x°
∵ m∠B = (3 x -60)°
∵ m∠A = m∠B
- Substitute the values of the angles
∴ x = 3 x - 60
- Add 60 to both sides
∴ x + 60 = 3 x
- Subtract x from both sides
∴ 60 = 2 x
- Divide both sides by 2
∴ x = 30
∵ m∠A = x
∴ m∠A = 30°
The measure of angle A is 30°
Learn more:
You can learn more about vertical angles in brainly.com/question/1599887
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