find all the ways you can find to fit the three shapes together so that there is at least one line of symmetry for the overall outline of the combined shape
you can start off with a rule that edges must meet whole edges and then maybe relax this rule later so that half edges meet
Puntmat I now know there are 13 solutions to this, with 19 if half square meeting is allowed
(5) 9 solutions (8 different outlines)
these are Puntmat's 13 solutions for puzzle (1)
many thanks to them for their and their student's fine work in finding so many solutions!
and another 6 if you allow 'half square' joins