A = (4, 5) B = (-2, 1)
Midpoint of A and B

Distance from A to B

Equation of line through AB


Line parallel to AB (same slope as AB) through point (3, -5)

AB is perpendicular to A'B' so slopes are opposite reciprocals
A' = (3, 0)
B' = (-1, 6)
C = (1, 3)
C' = (7, 3)
D = (5, 3)
D' = (5, 1)