The Elongated Pentagonal Rotunda


The elongated pentagonal rotunda is the 21st Johnson solid (J21). It has 30 vertices and 27 faces (10 equilateral triangles, 10 squares, 6 pentagons, and 1 decagon).

The elongated pentagonal
rotunda

The elongated pentagonal rotunda can be constructed by attaching a decagonal prism to a pentagonal rotunda (J6), lengthening it; hence the name elongated.

Projections

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

Projection Envelope Description
Regular decagon

Top view.

Octagon

Front view.

Heptagon

Side view.

Coordinates

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

where φ=(1+√5)/2 is the Golden Ratio.


Last updated 13 Apr 2018.

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