Proof without words: Law of cosinus

http://dmentrard.free.fr/GEOGEBRA/Maths/coslaw1MD.html
[url=http://dmentrard.free.fr/GEOGEBRA/Maths/coslaw1MD.html]http://dmentrard.free.fr/GEOGEBRA/Maths/coslaw1MD.html[/url]
– Daniel Mentrard

Information: Proof without words: Law of cosinus