Regular Tetrahedron or regular tetrahedron or regular tetrahedron or regular triangular pyramid is a regular polyhedron with four equilateral triangular faces, and three edges emanating from each vertex.
$$S_{0}= \frac{\sqrt{3}}{4}a^{2}$$
where,
a— length of the tetrahedron edge.
$$S= 4S_{0} = \sqrt{3} a^{2}$$
where,
a— length of the tetrahedron edge.
1. via edge length:
$$V=\frac{\sqrt{2}}{12} a^{3},$$
a,b,c— lengths of the tetrahedron edges.
2. via base area and height:
$$V=\frac{1}{3}S_{0} h,$$
S0— Base area of the tetrahedron.
h— Height of the tetrahedron.