



 
Try working backwards: Suppose you are given the trapezoid ABCD with AD parallel to BC and the four sides all having your desired lengths. Draw DC' parallel to AB with C' on BC. Then ABC'D is a parallelogram (with BC' equal in length to AD). That means C'C = CB  AD. Now you know how to work forwards: Start with triangle DC'C with side lengths DC' = AB, C'C = CB  AD, and CD. Chris  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 