Golden Ratios Inside the Pentagon

Pentagons and the pentagrams (5 pointed star) they contain are not taught enough, IMO.   There are so many cool properties, including its relationship to the triangles it contains: the 36-72-72 and the 36-36-108 triangles.   And the relationship to the golden ratio.

(There’s a typo near the top.  It should read “180-108=72” referring to angle <BCA.)

img_20170926_150028.jpg

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s