The question is asked in a textbook. I tried to answer the question by assuming A={(2,2),(1,1),(3,1)} B={(1,1),(3,3)} So when I did Cartesian product AXB, I got {(2,1),(1,1,(3,3),(3,1),(1,3),(3,2),(2,3),(1,2),(2,2)} which translated to a Square. Am I correct? Will that hold true for all the Cartesian products of a triangle and a line segment? How to prove in general? 
Thanks to @PaulSinclair it happens to be a triangular prism; line segment is one dimensional and a triangle is two dimensional, when Cartesian product(all possible ordered pairs) is taken, it results in a three dimensional triangular prism