#B4----------------------------------------------
plane p 0 0 0 1 0 0
pcylinder p p 15 30
profile p2 o 10 -10 5 l 10 c 5 90 l 10 d -1 0 l 20 \
d 0 -1 l 10 c 5 90
prism p2 p2 0 0 20
bfuse f p p2
nexplode f f
depouille result f 0 0 1 f_4 1 0 0 25 0 0 1

set square 4980.52