The five corners of the pentagon constitute alternate corners of the decagon.
From the en.wikipedia.org
A polygon with ten sides is a decagon, and 10 is a decagonal number.
From the en.wikipedia.org
It features a concrete walkway that leads visitors to a 30-foot, decagon-shaped concrete pad.
From the charlotteobserver.com
Join these points to the adjacent new points to form the decagon.
From the en.wikipedia.org
As for other itmes, the most interesting one I spot is the regular decagon that appears a few times.
From the tierneylab.blogs.nytimes.com
Where each line cuts the circle is a vertex of the decagon.
From the en.wikipedia.org
He also found architectural scrolls describing how girih designs were assembled from five regularly shaped tiles, including a bowtie shape, a rhombus, a pentagon, an elongated hexagon, and a decagon.