∠A∠A and ∠B∠B are vertical angles with m∠A=xm∠A=x and m∠B=5x−80m∠B=5x−80 . What is m∠Am∠A ?
Vertical angles are the pairs of opposite angles made by two intersecting lines. One interesting feature of these angles is that they have equal measurements. Therefore we can solve m∠A as follows:
m∠A = m∠B
x = 5x - 80
6x = 80
x = 40/3
m∠A = 40/3
The Vertical Angles Theorem states that if two angles are vertical angles, then they are congruent .Given <A and <B are vertical angles so they are equal.
<A=<B.
Measure of <A=x and <B=5x-80
Or 5x-80=x
Adding 80 both sides
5x-80+80=x+80
5x=x+80
Subtracting x both sides
5x-x=x-x+80
4x=80
Dividing both sides by 4
x=20
Measure of <A= x= 20 degrees.