∠a and ∠b are vertical angles with m∠a=x and m∠b=5x−80 .

what is m∠a ?

The measure angle A is .

Step-by-step explanation:

Given Information:

According to the Vertical Angle Theorem, the two opposite vertical angles are congruent due to the intersection of two lines.

Therefore, equating  we get,

Therefore, the measure angle A is .

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we know that

Vertical Angles are the angles opposite each other when two lines cross. They are always congruent to one another

in this problem

∠A and ∠B are vertical angles

so

∠A=∠B

we have

∠A= 

∠B=

equate angle A and angle B

solve for x

therefore

the answer is

the measure of angle A is