I need an algorithm (3D), which would determine if point belongs to a triangle. And also if it does I want to know the distance between some point in triangle and a another point. Triangles can be slightly rotated, but if point is outside triangles vertical reach then it should not be considered as inside the triangle.
Now I realize, my question probably doesn’t make a lot of sense so here’s the picture, which explains what I want.

Grey lines display, which way triangle is actually facing.
It’s not actually that I want to check if a point is within a prism, but I after i find out if point lies within triangle (not exactly, might be on top of or below) then I need to find the distance between point and a triangle it belongs to. And depending on the distance function will finally return if that point is inside the triangle. A little inaccuracy is allowed. However, maybe I want to check if a point is within a prism, but do not know that. I am just horrible at math so I am not aware of correct terminology.
This seems like the 3D equivalent of Data structure to query points which lie inside a triangle.
You could use the same method in 3D: in 3D, a plane cuts the space in two halves: a point is either at one side of the plane or at the other side. The wedge-shape is a collection of planes: just combine the which_side_of_the_plane information for a given point with all the planes that build up the wedge.