I have two 3D planes: A1*x + B1*y + C1*z + D1 = 0 and A2*x + B2*y + C2*z + D2 = 0. If you set them equal to each other it should be at the intersection. This leads to another Plane: (A1 - A2)*x + (B1 - B2)*y + (C1 - C2)*z + (D1-D2) = 0. What I want is the line of intersection in vector and parametric form. This is not a homework problem. It is for personal knowledge. Is this Possible?