diangle

plural diangles

1. A digon or bigon; a two-sided shape.

   The diangle ABCD indicates the entire duration of life, A and C being its commencement and its termination.

   1853, “The Science of Medicine”, in The Journal of Psychological Medicine and Mental Pathology, page 241

   2 more examples

   Now the wedge 1,2 is mapped into the exterior of the circular diangle C,S₁,1,O,2,S₂,C; both regions are indicated by a shading of the boundary. We now seek the images of the reflected wedges.

   1949, Arnold Sommerfeld, translated by Ernst G. Strauss, Partial Differential Equations in Physics, volume 1, Academic Press, page 319

   Let B be a region of F bounded by a closed polygon comprised of segments of geodesics of surface F, and let hₙ be a sequence of nondegenerate diangles of region B whose sides are geodesics of region B and which converge to diangle hₙ.

   1969, Siberian Mathematical Journal, Kluwer/Plenum Publishers, page 107

   Synonyms: digon, bigon, biangle