Philippi Lansbergii Triangvlorvm geometriae libri qvatvor : in quibus novâ & perspicuâ methodo, & apodeixei [romanized], tota ipsorum triangulorum doctrina explicatur ..

Lansberge, Philippe van, 1561-1632 · 1631 · Amsterdami : Apud Gvilielmvm Blaevw · 26 pictures

A 1631 Latin treatise on plane and spherical trigonometry by the Flemish mathematician Philippe van Lansberge, printed in Amsterdam by Willem Blaeu for scholars and students of geometry. The four pictures are geometric diagrams of triangles on curved arcs, plus a circle with an inscribed shaded ellipse, drawn in fine black line with lettered vertices and tick-mark equal-length notation, giving a designer clean, schematic linework and letter labels to borrow.

Trigonometry -- Early works to 1800

Internet Archive · Fisher - University of Toronto · Public domain (published before 1931) · More from this library