On: Hilariously fast volume computation with the divergence theorem (2018)

[lern_too_spel]

You might be interested in the shoelace formula and its generalization to n dimensions. https://en.wikipedia.org/wiki/Shoelace_formula

[lern_too_spel → lern_too_spel]

For this particular case of 3 dimensions, I found

Newson, H. B. “On the Volume of a Polyhedron.” Annals of Mathematics, vol. 1, no. 1/4, 1899, pp. 108–10. JSTOR, https://doi.org/10.2307/1967277