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## Main Question or Discussion Point

Hi there,so i'm trying to write a vb.net program which will tell me whether a cartesian point in 2D lies inside or outside of a triangle.

I'm not looking for the code or anything, i'm merely wondering how one does this type of calculation manually?

could the cross product be used?if the results of all three cross products point in the same direction the point lies inside the triangle, otherwise it lies outside the triangle???i read this in a forum but i don't honestly understand the logic behind it?

or is there a much simpler way i have overlooked?

any advice would be much appreciated

debs

I'm not looking for the code or anything, i'm merely wondering how one does this type of calculation manually?

could the cross product be used?if the results of all three cross products point in the same direction the point lies inside the triangle, otherwise it lies outside the triangle???i read this in a forum but i don't honestly understand the logic behind it?

or is there a much simpler way i have overlooked?

any advice would be much appreciated

debs