Once we have the edges constructed, we can start to build the sides of the solid. [br][br]The metaphor is to imaging stretching on edge linearly to the other edge. [br]Another edge is to consider "mixing" the two edges linearly.[br][br]The command to do this side is [b]Surface[u*1 + (1 - u)*t, u*0 + (1 - u)*0, u*0 + (1 - u)*f(t), u, 0, 1, t, 1, 5][/b]