Math: Finding a point that is perpendicular to another point.

[aaranaf]

So here's what I want to do. I want to find the point in 2d-space for C.
I have the point A and B and the distance from B to C.
I know C is perpendicular to B. If someone could point me in the right direction on this it would be greatly appreciated.

[The Hatchet]

Go to google and put in "find point perpendicular to line"

[rgrant1993]

We need to know the data you have recorded inorder to know the data we need to find.

[Grimshaw]

(direction from A to B)
V = B - A
V' = normalize(V)

(vector orthogonal to V' - perpendicular)
O = (-V'y, V'x)

(finally find point C by going from B in the orthogonal direction)
C = B + O * distance

I am a little fuzzy right now but if something is wrong here ill get back to you

[gostron]

May I add that knowing the distance and that it's perpendicular gives your two points, one for each side.

for a vector defined by (a,b) an orthogonal vector would be (-b, a) (so I do agree with Grimshaw, just to say it a bit differently)