Which literature the relation theorem between the determinant and the volume is appered firstly in

       The theorem on the relation between the determinant and the geometry volume can be presented as the following two versions.

      [Theorem 1]. If $A_{n}$ is a $n$ -dimensions vector set $\{a_{1},a_{2},\cdots,a_{n}\}$ and paramters $c_{i},i=1,2,\cdots,n$ are in the interval [0,1], the parallel polyhedron spanned by the vectors $a_{i}$ with the parameters $c_{i}$ can be described as

$C_{n}(A_{n})=\left\{ \left.c_{1}a_{1}+c_{2}a_{3}+\cdots+c_{n}a_{n}\right|\forall c_{i}\in[0,1],i=1,2,\cdots,n\right\}$

The volume of the polyhedron $C_{n}(A_{n})$ in the $n$ -dimensions space can be computed by the following equation.

$V_{n}(C_{n}(A_{n}))=\left|\mathrm{det}(A_{n})\right|$

       [Theorem 2]. Let the vertexes of the geometry in the $$ $n$ -dimensions space is $a_{i}(i=1,2,...,n)$ , and the vloume the geometry is

$V_{n}(E_{n}(A_{n}))=\frac{1}{n!}\left|\mathrm{det}(A_{n})\right|$

where $A_{n}=[a_{1},a_{2},\cdots,a_{n}]$ .

      Which literature the above two theorem on the relation between the determinant and the volume is appered firstly in? Which colleage can tell me? Thanks a lot.