Hi folks,

I have been given the vector equation of two lines and then asked to find the point of intersection A. Then I am given two more lines and asked to show that these lines form the other two sides of a quadrilateral. I am not sure how to do this (please help). We are then asked to find the other 3 points of intersection (B, C and D - which was no problem) and then to decide whether or not the points lie in a plane. Again no problem. I am giving this extra information in case any of it helps with the decision about the lines forming a quadrilateral.

many thanks