We are given lines l and m and a transversal line to those two given lines.
We need to explain which of the following facts, if true, would allow you to prove that lines l and m are parallel.
Let us describe each given options.
A)m<2+m<4=180 degrees.
m<2 and m<4 makes a line pair. So, it doesn't prove if lines l and m are parallel.
B)m<1=m<8
m<1 and m<8 are Alternate Exterior Angles and when Alternate Exterior Angles equal lines are parallel.
C)m<6+m<3=180 degrees
This statement can't be true. Alternate interior angles can't be sum upto 180 degrees.
D)m<7=m<6
Those are vertical angles, that doesn't make the l and m parallel.
Therefore, only B option is correct option.
B)m<1=m<8.
