Whats the question? its not there
Answer:
A. Right angle -- if you multiply the slopes of 2 intersecting lines and you "-1" then the lines are perpendicular - in this case the line in quadrant 3 has a slope of "1" and the line in quadrant 4 has a slope of "-1", hence their product is "-1" and the angles formed at the intersection of the lines are right angles.
Step-by-step explanation:
Use the triangle angle theorem:
All interior angles of a triangle equal 180 degrees.
If you use the theorem you should get the first one 19,70,91
