Step-by-step explanation:
horizontal lines will have a gradient(m) of 0
so if m=0 , the line is horizontal
formula to find m:
m=y2-y1 / x2-x1
insert coordinates into formula

As m=0 , therefore it is a horizonta line.
hope this helps..
3/1 i think
-----------------
Answer:
Theorem 10.5: If two parallel lines are cut by a transversal, then the exterior angles on the same side of the transversal are supplementary angles.
Answer:
Correct.
Step-by-step explanation: