
| Model No. 233 | FA: 40 |
| Description: Areas and curves of constant width and constant perimeter; in addition straps to push through | |
| RE: M3 319,325,339,347 Jessen: Über konvexe Punktmengen konstanter Breite. Math. Zeitschrift B 29 Heft 2/3 | Category: Other exhbits |
| RU: E VI 13-25 | |