#F2----------------------------------------------
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_12 1 p_4
nexplode p f
depouille result p 0 0 1 p_8 2 0 0 0 0 0 1 \
p_1 1 0 0 10 0 0 1

checkprops result -s 1273.54