Answer:
Subtraction property of equality.
1 and 5 are corresponding angles, so both have the same measure:
m 1 = m 5
m 1 = 65º
Answer: option D. 65º.
I hope this helps. =)
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.
Let x = small number
y=large numebr
x+y = 90
y-4x=15
substitute
we get:
x=21
y=90-21 = 69
