Elongated square pyramid

In geometry, the elongated square pyramid is one of the Johnson solids (J_8). As the name suggests, it can be constructed by elongating a square pyramid (J_1) by attaching a cube to its square base. Like any elongated pyramid, it is topologically (but not geometrically) self-dual. The following formulae for the height (), surface area () and volume () can be used if all faces are regular, with edge length : The dual of the elongated square pyramid has 9 faces: 4 triangular, 1 square and 4 trapezoidal. The elongated square pyramid can form a tessellation of space with tetrahedra, similar to a modified tetrahedral-octahedral honeycomb.