Nel 1942 Traing Wang e Chuan-Chin Hsiung hanno dimostrato che esistono solo 13 configurazioni diverse del tangram che producono figure convesse
Soluzione
GLOBAL ox, oy
TO origin x y
GLOBAL ox, oy
ox = 150+x*20
oy = 600-y*20
END
TO place x y
POSITION [ox+x*20, oy-y*20]
END
TO line x y x2 y2
PENUP place x y
PENDOWN place x2 y2
END
TO tri x y x2 y2 x3 y3
line x y x2 y2 place x3 y3 FILL
END
TO box x y x2 y2 x3 y3 x4 y4
line x y x2 y2 place x3 y3 place x4 y4 FILL
END
PICTURE “convex_tangram_shapes.svg” [
PENSIZE 1
HIDETURTLE
PENCOLOR “WHITE”
FILLCOLOR “BLACK”
origin 18 2
tri 3 0 3 2 1 2
tri 1 2 1 3 2 2
tri 2 2 0 4 2 4
tri 0 4 1 5 2 4
tri 2 4 2 3 3 3
box 3 3 3 2 2 2 2 3
box 1 2 1 3 0 4 0 3
origin 19 8
tri 0 2 2 2 2 0
tri 0 4 0 5 1 4
tri 0 2 0 3 1 3
tri 0 2 1 3 2 2
tri 0 5 2 5 2 3
box 0 3 0 4 1 4 1 3
box 1 3 1 4 2 3 2 2
origin 12.5 4
tri 0 0 0 2 2 0
tri 0 2 2 2 2 0
tri 2 0 2 1 3 1
tri 2 0 3 1 4 0
tri 4 1 4 2 3 2
box 2 1 2 2 3 2 3 1
box 3 1 3 2 4 1 4 0
origin 15 7
tri 0 2 2 2 2 0
tri 0 2 2 2 2 4
tri 0 3 0 4 1 4
tri 0 5 0 6 1 5
tri 1 5 1 3 2 4
box 0 4 0 5 1 5 1 4
box 0 2 0 3 1 4 1 3
origin 11 0
tri 0 1 2 1 2 3
tri 2 1 2 3 4 3
tri 1 0 1 1 2 0
tri 1 1 3 1 2 0
tri 2 1 3 2 3 1
box 0 0 0 1 1 1 1 0
box 3 1 3 2 4 3 4 2
origin 9 3
tri 0 2 2 2 0 4
tri 0 4 2 4 2 2
tri 0 4 1 5 2 4
tri 0 1 1 1 1 0
tri 1 1 1 2 2 2
box 1 0 1 1 2 2 2 1
box 0 1 0 2 1 2 1 1
origin 11 7
tri 0 2 2 2 2 0
tri 0 4 2 4 2 6
tri 0 2 0 3 1 3
tri 0 2 1 3 2 2
tri 1 4 2 4 2 3
box 0 3 0 4 1 4 1 3
box 1 3 1 4 2 3 2 2
origin 5 0
tri 0 0 0 2 2 0
tri 0 2 2 2 2 0
tri 0 2 1 3 1 2
tri 2 0 3 1 2 2
tri 2 0 3 0 3 1
box 1 2 1 3 2 3 2 2
box 2 2 2 3 3 2 3 1
origin 4 4
tri 0 2 2 2 2 0
tri 0 2 2 4 2 2
tri 2 4 2 3 3 3
tri 2 1 2 2 3 2
tri 3 1 3 3 4 2
box 2 2 2 3 3 3 3 2
box 2 0 2 1 3 2 3 1
origin 5 10
tri 0 0 0 1 1 0
tri 0 1 3 1 1 0
tri 0 2 1 3 1 2
tri 1 1 1 3 3 1
tri 1 3 3 3 3 1
box 0 1 0 2 1 2 1 1
box 1 0 2 1 3 1 2 0
origin 0 0
tri 0 1 1 2 1 1
tri 1 0 1 2 3 0
tri 1 2 3 2 3 0
tri 1 2 2 3 3 2
tri 3 0 3 1 4 0
box 0 0 0 1 1 1 1 0
box 3 1 3 2 4 1 4 0
origin 0 3
tri 0 0 0 2 1 1
tri 0 3 1 3 1 2
tri 0 4 1 5 1 4
tri 1 3 1 5 3 3
tri 1 1 1 3 3 3
box 0 2 0 3 1 2 1 1
box 0 3 0 4 1 4 1 3
origin 0 9
tri 0 0 0 2 2 2
tri 0 2 0 4 2 2
tri 2 2 1 3 3 3
tri 0 4 1 4 1 3
tri 2 3 2 4 3 4
box 1 3 1 4 2 4 2 3
box 2 3 3 4 4 4 3 3
]