Complex sentence: In spherical geometry, a finite henagon can be drawn by placing a single vertex anywhere on a great circle this forms a henagonal dihedron, Schläfli symbol, with two hemispherical henagonal faces which share one 360 degree edge and one vertex.
Split into simpler sentences: In spherical geometry, a finite henagon can be drawn by placing a single vertex anywhere on a great circle. This forms a henagonal dihedron, Schläfli symbol, with two hemispherical henagonal faces which share one 360 degree edge and one vertex.