Elongated triangular bipyramid

The following formulae for volume (${\displaystyle V}$), surface area (${\displaystyle A}$) and height (${\displaystyle H}$) can be used if all faces are regular, with edge length a:

${\displaystyle V=\left({\frac {1}{12}}\left(2{\sqrt {2}}+3{\sqrt {3}}\right)\right)\cdot a^{3}\approx 0.668715...a^{3}}$[3][4]

${\displaystyle A=\left({\frac {3}{2}}\left(2+{\sqrt {3}}\right)\right)\cdot a^{2}\approx 5.59808...a^{2}}$[3][4]

${\displaystyle H={\frac {3+2{\sqrt {6}}}{3}}\cdot a\approx \cdot 2.63299...a}$[4]

Dual polyhedron

The dual of the elongated triangular bipyramid is called a triangular bifrustum and has 8 faces: 6 trapezoidal and 2 triangular.

Dual elongated triangular bipyramid	Net of dual

• Weisstein, Eric W., "Elongated triangular bipyramid" ("Johnson solid") at MathWorld.