This has been known for years. The animal skin sails that they made were always perfect 30-60-90 triangles. They knew to make the bottom edge 1/2 the hypotenuse.
This is the origin of the term “fur sail sine”.
17 posted on 09/21/2009 8:44:19 AM PDT by OSHA
(I want to meet the man that put the cat IN the bag.)