#F1----------------------------------------------
polyline p 2 0 0 10 0 0 10 0 20 2 0 20 2 0 0 
mkplane p p
revol p p 0 0 0 0 0 1 180
nexplode p e
blend p p 2 p_1 2 p_12
nexplode p f
depouille result p 0 0 1 p_8 3 0 0 0 0 0 1

set square 1198.82