Commit 2021-02-28 20:56 ac3c4787
View on Github →feat(archive/100-theorems-list/9_area_of_a_circle): area of a disc (#6374)
Freek № 9: The area of a disc with radius r is πr².
Also included are an of_le version of FTC-2 for the open set and the definition nnreal.pi.
Co-authored by @asouther4 and @jamesa9283.