Wikipedia contributors. (2023, September 29). Pentagon. In Wikipedia, The Free Encyclopedia. Retrieved October 31, 2023, from https://en.wikipedia.org/w/index.php?title=Pentagon&oldid=1177778936
https://github.com/davepinch/pinchy.cc/blob/master/content/topics/mathematics/shapes/pentagon/properties/en.wikipedia.org.snippet-regular-pentagons-1-1.md
Pentagon (Wikipedia) In geometry, a pentagon (from Greek πέντε (pente) ‘five’ and γωνία (gonia) ‘angle’) is any five-sided polygon or 5-gon. The sum of the internal angles in a simple pentagon is 540°.