Francœur, L.-B. (Louis-Benjamin), 1773-1849, Fowle, William Bentley, 1795-1865. Elements of linear perspective · Boston : Hilliard, Gray, Little & Wilkins · leaf 20
Se ee 39. Cut a rectangle into halves. (fig. 23.) This will make two angles, whose exactness may be tested by an eighth part of a circle of pasteboard, the rectangle being quarter of a circle, as was stated under Prop. 24. 40. Cut an acute angle into two equal parts. (fig.24.) 41. Double an angle.… … 42. Triple an angle. (fig. 25.) 43. Cut anangle into three equal parts. (fig. 25.) 44. Cut an angle into six equal parts. (fig. 26.) These three propositions need no explanation. 2%
Drawing · Geometrical drawing
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
