The routine faces returns the faces of the given polyhedron.

Each face is represented as a list of coordinates of its vertices which are listed in counter-clockwise order as viewed from outside the polyhedron.

The command with(geom3d,faces) allows the use of the abbreviated form of this command.

$\mathrm{with}\left(\mathrm{geom3d}\right)\:$

$\mathrm{tetrahedron}\left(t\,\mathrm{point}\left(o\,0\,0\,0\right)\,2\right)$

$t$

$\mathrm{faces}\left(t\right)$

$\left[\left[\left[\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\right]\,\left[\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\right]\,\left[-\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\right]\right]\,\left[\left[\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\right]\,\left[-\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\right]\,\left[\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\right]\right]\,\left[\left[\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\right]\,\left[-\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\right]\,\left[-\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\right]\right]\,\left[\left[\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\right]\,\left[-\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\right]\,\left[-\frac{2\sqrt{3}}{3}\,\frac{2\sqrt{3}}{3}\,-\frac{2\sqrt{3}}{3}\right]\right]\right]$