it is 2 single plane roofs.
you could just edit your roofs.
move the pitching line from the out edge to be diagonal across the middle
click on the middle of the pitching line and drag it off the edge
move the ends one by one.
then edit the roof shape so the corner is on the ridge line.
click on the node and move it
then adjust the height of the roof so it is at the top
you can just type in the height
do the same to the other roof
you can adjust the pitch in 3D by grabbing the outer node and moving to the desired height
i hope this helps
I am up to page 4,078 of Archicad 26 Reference Guide, (Worksheet and Detail Tool Settings), but i got to read it all 😞