Riemann and area of a polar curve

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

Information: Riemann and area of a polar curve