Elongated square pyramid

Elongated square pyramid
Type	Johnson J7 – J8 – J9
Faces	4 triangles 1+4 squares
Edges	16
Vertices	9
Vertex configuration	${\displaystyle 4\times (4^{3})}$ ${\displaystyle 1\times (3^{4})}$ ${\displaystyle 4\times (3^{2}\times 4^{2})}$
Symmetry group	${\displaystyle C_{4v}}$
Dihedral angle (degrees)	triangle-to-triangle: 109.47° square-to-square: 90° triangle-to-square: 144.74°
Dual polyhedron	self-dual
Properties	convex, composite
Net

In geometry, the elongated square pyramid is a convex composite polyhedron constructed by attaching the square base of an equilateral square pyramid to one of the square faces of a cube; this is called an elongation of the pyramid. One square face of each parent body is thus hidden, leaving five squares and four equilateral triangles as faces of the composite. It is an example of a Johnson solid, a convex polyhedron whose faces are all regular, indexed as ${\displaystyle J_{8}}$.