1 min readJan 23, 2017
It’s 60 degrees because you can tessellate a third coin into the negative space between the two coins, leaving a single equilateral triangle.
No, I don’t know the geometry required to “prove” that.
But I know I’m right. ;)
Written by Nicole Dieker
Freelance writer at Vox, Bankrate, Haven Life, & more. Author of The Biographies of Ordinary People.