Question

ZA and ZB are vertical angles with MZA = X and mZB = 3x - 60.What is mZA?​

Answer 1

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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