Numberphile | Pentagons and the Golden Ratio - Numberphile @numberphile | Uploaded 4 years ago | Updated 1 hour ago
Continuing on from Zvezda's previous video about Ptolemey's Theorem (see: youtu.be/bJOuzqu3MUQ) now we use it to prove some cool stuff with pentagons and equilateral triangles.
More links & stuff in full description below ↓↓↓

Zvezda's Numberphile playlist: http://bit.ly/zvezda_videos

Zvezda's webpage: https://math.berkeley.edu/~stankova/

Golden Ratio: youtu.be/sj8Sg8qnjOg

Epic Circles: youtu.be/sG_6nlMZ8f4

Triangle Magic Highway: youtu.be/wVH4MS6v23U

Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile

We are also supported by Science Sandbox, a Simons Foundation initiative dedicated to engaging everyone with the process of science. simonsfoundation.org/outreach/science-sandbox

And support from Math For America - mathforamerica.org

NUMBERPHILE
Website: http://www.numberphile.com
Numberphile on Facebook: http://www.facebook.com/numberphile
Numberphile tweets: twitter.com/numberphile
Subscribe: http://bit.ly/Numberphile_Sub

Videos by Brady Haran

Patreon: http://www.patreon.com/numberphile

Numberphile T-Shirts and Merch: teespring.com/stores/numberphile

Brady's videos subreddit: http://www.reddit.com/r/BradyHaran

Brady's latest videos across all channels: http://www.bradyharanblog.com

Sign up for (occasional) emails: http://eepurl.com/YdjL9