TITLE: general formula for volume of a simplex?
QUESTION [5 upvotes]: I am looking for a general formula to calculate the volume of a euclidean simplex in any number of dimensions. On Wikipedia I found that a formula similar to Heron's formula can be applied to tetrahedrons as well as triangles, can this perhaps be abstracted to a formula for the volume of an n-simplex? or perhaps another type of formula?
(Wikipedia page: http://en.wikipedia.org/wiki/Heron's_formula#Heron-type_formula_for_the_volume_of_a_tetrahedron)

REPLY [8 votes]: See http://mathworld.wolfram.com/Cayley-MengerDeterminant.html.  Given an $n$-simplex with vertices $v_i$, put $B_{ij}=\|v_i-v_j\|^2$ for $0\leq i,j\leq n$.  Then put $B_{n+1,j}=B_{i,n+1}=1$ except $B_{n+1,n+1}=0$.  The volume is then 
$$ V = \sqrt{(-1)^{n+1}\frac{\det(B)}{2^nn!^2}} $$