I have a triangle in 2d space with points A(x,y), B(x,y), and C(x,y). I also have the point P(x,y). How do I find if the point P is in the triangle? If it involves anything like a cross product or dot product then please include details on how to do that. It's for a computer program and I have the variables ax,ay,bx,by,cx,cy,px,py so if someone could provide an algorithm that would be great. Thanks in advance.