basic Fyzics HELP

Hey, I just can't figure out how to make a falling point hit & stop on a triangle.

Please I'm stuck with this problem for like 3weeks found no solution yet.

Do you know how to find the collision point between the ray representing the "way" of the point and the triangle? Otherwise, look at the source code of any 3D engine written in Java or in nehe.gamedev.net to find an implementation of such an algorithm.