Question

A and B are vertical angles with mA= x and mB= 4x - 30.

What is mA?
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Answer 1

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Answer:

10°

Explanation:

Vertical angles have the same measure, so ...

∠A = ∠B

x = 4x -30

30 = 3x . . . . . . . add 30-x to both sides

10 = x = ∠A . . . . divide by 3

The measure of ∠A is 10°.