I am struggling with this exercise.
Given is the Midpoint M of a square ABCD and two straight lines g and h. One should construct the square ABCD having A on g and C on h 1
I know I am looking for A and C to have the same distance to M.
Someone knows how to do this? Bests

Draw a line from $M$, parallel to one of those straight lines, let's say parallel to $h$ and call the point $P$ the intersection with the line $g$ .
Mark $A$ on $g$ such that $AP=PO$.
Line $AMC$ is the diagonal of your square.