The Elongated Pentagonal Pyramid

The elongated pentagonal pyramid is the 9th Johnson solid (J9). It has 11 vertices, 20 edges, and 11 faces (5 equilateral triangles, 5 squares, and 1 pentagon).

The elongated pentagonal

The elongated pentagonal pyramid can be constructed by attaching a pentagonal pyramid to a pentagonal prism.

Attaching a second pentagonal pyramid to the other end of the pentagonal prism produces the elongated pentagonal bipyramid (J16).


Here are some views of the elongated pentagonal pyramid from various angles:

Projection Envelope Description
Regular pentagon

Top view.


Side view.


Front view.


The Cartesian coordinates of the elongated pentagonal pyramid with edge length 2 are:

where φ=(1+√5)/2 is the Golden Ratio.

Last updated 18 Jun 2019.

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