Problem 450. What is the distance from point P(x,y) to the line Ax + By + C = 0?

Given a point, P(x,y), find the distance from this point to a linear line.

INPUTS: x, y, A, B, C

OUTPUTS: d, the distance which of course should always be positive.

EX:
>>x=2; y=2; A=2; B=2; C=-4;
>>d = normalLen(x,y,A,B,C)
d = 1.4142