Using the ruler and the compass,  to construct a trapezoid which has the bases congruent to the two given segments and the lateral sides congruent to the two other given segments.
It is assumed that the four given segments satisfy all necessary conditions in order such a trapezoid could exist.  You may think that the trapezoid did exist with the
given bases and the lateral sides and was de-assembled into separate segments,  so that now you need to construct  (to restore)  it again using the ruler and the compass
Construct 2 parallel lines of different sizes...join the ends and thats a trapezium...