Memorize some trigonometric values with the hand

http://dmentrard.free.fr/GEOGEBRA/Maths/MemoratioMD.html
[url=http://dmentrard.free.fr/GEOGEBRA/Maths/MemoratioMD.html]http://dmentrard.free.fr/GEOGEBRA/Maths/MemoratioMD.html[/url]
– Daniel Mentrard

Information: Memorize some trigonometric values with the hand