Keywords: John Landen.jpeg en Portrait of John Landen 1719-1790 british mathematician century 18 Mactutor History of Mathematics http //turnbull mcs st-and ac uk/~history/PictDisplay/Landen html author other versions Custom license marker 2015 03 01 PD-old-100 Uploaded with UploadWizard Mathematicians from England 1719 births 1790 deaths |