Where we had left off we had used the information from these two lines to figure out two lines to figure out two vectors which were really just, almost you can say, were two position vectors lying in this white plane and we took their cross-product to find a vector that's perpendicular, that's normal to this entire white plane and that was the vector d there and vector d will have to sit, especially to visualize it, you can always position a vector anywhere you want. 