Question

I have been stuck with this one, and i would like to how to solve this.

In each case, determine whether line AB is parallel or perpendicular to CD.
(a) A(0, 0), B(0, 1), C(0, 0), D(1, 0).
(b) A(0, 1), B(2, 3), C(4, 5), D(6, 7).

Answer 1

a) AB is parallel CD from graphic;
b) m AB = (3-1)/(2-0) => m AB = 1; m CD = (7-5)/(6-4) => m CD = 1 => m AB = m CD => AB is parallel CD;