use b and c first
b(2, -5), c(4, 6)
M = (Yb - Yc)/(Xb - Xc)
M = (-5 - 6) / (2 - 4)
M = -11/-2 = 11/2
I choose 'b' to get the equation
y + 5 = 11/2(x - 2)
y + 5 = 11/2x - 22/2
y = 11/2x - 11 - 5
y = 11/2x - 16
the slope of the perpendicular line is the negative reciprical.
M of original line is 11/2 negative reciprical is
-2/11 and use the point c(-1, 3)
y - 3 = -2/11(x + 1)
y - 3 = -2/11x - 2/11
y = -2/11x - 2/11 + 3
y = -2/11x + 31/11 is the perpendicular line