ellipse w1 0 0 0 15 10
mkedge w1 w1 0 pi/2
trotate w1 0 0 0 1 0 0 90
polyline w2 0 0 10 0 0 -10 25 0 -10 15 0 0
wire w w1 w2
mkplane w w
revol s w 0 0 0 0 0 1 90

OFFSETSHAPE -1 {s_4 s_5} $calcul $type

checkprops result -v 4385.14
