box b1 0 0 0 1 1 1
dset a30 atan2(1,2)*180/pi
dset r sqrt(5)/4
box b2 0.25 0 0 1.5*r r 1
trotate b2 0.25 0 0 0 0 1 a30

bop b1 b2
bopfuse result

set square 6