In
spherical trigonometry, triangles on the surface of a
sphere are studied. The spherical triangle identities are written in terms of the ordinary trigonometric functions but differ from the plane
triangle identities.
Hyperbolic functions in Euclidean geometry: The
unit circle is parameterized by (cos t, sin t) whereas the equilateral
hyperbola is parameterized by (cosh t, sinh t).
Schläfli orthoschemes - right simplexes (right triangles generalized to n dimensions) - studied by
Schoute who called the generalized trigonometry of n Euclidean dimensions polygonometry.
^Aslaksen, Helmer; Huynh, Hsueh-Ling (1997), "Laws of trigonometry in symmetric spaces", Geometry from the Pacific Rim (Singapore, 1994), Berlin: de Gruyter, pp. 23–36,
CiteSeerX10.1.1.160.1580,
MR1468236
^Masala, G. (1999), "Regular triangles and isoclinic triangles in the Grassmann manifolds G2(RN)", Rendiconti del Seminario Matematico Università e Politecnico di Torino., 57 (2): 91–104,
MR1974445
In
spherical trigonometry, triangles on the surface of a
sphere are studied. The spherical triangle identities are written in terms of the ordinary trigonometric functions but differ from the plane
triangle identities.
Hyperbolic functions in Euclidean geometry: The
unit circle is parameterized by (cos t, sin t) whereas the equilateral
hyperbola is parameterized by (cosh t, sinh t).
Schläfli orthoschemes - right simplexes (right triangles generalized to n dimensions) - studied by
Schoute who called the generalized trigonometry of n Euclidean dimensions polygonometry.
^Aslaksen, Helmer; Huynh, Hsueh-Ling (1997), "Laws of trigonometry in symmetric spaces", Geometry from the Pacific Rim (Singapore, 1994), Berlin: de Gruyter, pp. 23–36,
CiteSeerX10.1.1.160.1580,
MR1468236
^Masala, G. (1999), "Regular triangles and isoclinic triangles in the Grassmann manifolds G2(RN)", Rendiconti del Seminario Matematico Università e Politecnico di Torino., 57 (2): 91–104,
MR1974445