Perpendicular on a line segment from a given point

Question

I want to calculate a point on a given line that is perpendicular from a given point.

I have a line segment AB and have a point C outside line segment. I want to ca

Answer 1

Since you're not stating which language you're using, I'll give you a generic answer:

Just have a loop passing through all the points in your AB segment, "draw a segment" to C from them, get the distance from C to D and from A to D, and apply pithagoras theorem. If AD^2 + CD^2 = AC^2, then you've found your point.

Also, you can optimize your code by starting the loop by the shortest side (considering AD and BD sides), since you'll find that point earlier.