Grigory MerzonTriangulate a cyclic polygon. “Japanese theorem”: the sum of inradii of triangles doesn't depend on the triangulation.
Moreover, this sum is constant in the “Poncelet family” of all polygons with the same incircle and circumcircle.
Frank Wappler@ocfnash
http://olivernash.org/2018/07/08/poring-over-poncelet/index.html
Awesome!
I'd love to find out about #Poncelet generalizations or related results in 3+1 dimensional flat #MinkowskiSpace, with
- all relevant edges along light cones (Are those "singular" and perhaps problematic, even in 3+1 D ?), and
- the \(n\)-sided polygon generalized to a #PingCoincidenceLattice (cmp. my sketch https://mathstodon.xyz/@MisterRelativity/109435130217990848 )