By Girard's Spherical Excess Formula, a spherical triangle on unit sphere with angles $A, B, C$ has area $$ A + B + C - \pi. $$ I would like to know, if there is a generalization for this formula to higher dimensions.

There is a thread on MathOverflow about calculating the volume of elliptical tetrahedron. It seems that for odd dimensions the problem is much complex. But one answer in that thread suggests that it is easier to get one for even dimensions. However I could not find any result through Google.

I really know very little about geometry. Any information regarding this problem would be appreciated.


See these notes by J. G. Heckman (he focuses on the hyperbolic case, but the spherical case is essentially identical).

| cite | improve this answer | |
  • $\begingroup$ The paper gives Reduction Formula for computing the volume of simplex of even dimension. But that formula depends on calculating volumes of simplici of all lower dimensions, not just lower even dimensions. Does this mean that this problem is not really solved for even dimensions also? $\endgroup$ – ablmf May 2 '14 at 14:23
  • $\begingroup$ It is an exercise to drop out the odd-dimensional terms... $\endgroup$ – Igor Rivin May 3 '14 at 1:59
  • $\begingroup$ @HassanJolany What is your point, exactly? $\endgroup$ – Igor Rivin May 14 '14 at 20:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.