Geometrymedium · Past Paper

What is the angle between the lines y = x and y = -x?

A0 degrees
B45 degrees
C90 degrees
D180 degrees

✓ Correct Answer: C90 degrees

Slope of y=x is m1=1. Slope of y=-x is m2=-1. Since m1*m2 = -1, the lines are perpendicular (90 degrees).

Share this question

More from Geometry