Science and art drawing : complete geometrical course ; consisting of plane and solid geometry, orthographic and isometric projection, projection of shadow's the principles of map projection, graphic arithmetic and graphic statics (1895)
Spanton, J. Humphrey (John Humphrey) · London : Macmillan · leaf 270
Fig. 56. B SPHERICAL TRIANGLES 249 The plane of the great circle which forms the equator hasan imaginary line passing through its centre at right angles toit, and terminated at the jpolcs on the surface of the sphere;this line is called the ^olar axis. Every great circle has an axis. In Fig. 57 the… … ¥\%. 57. planes forming this spherical triangle,—for instance, OA isperpendicular to the plane ah, OB to ccl, and OCto ef,—theirpoles will meet the surface of the sphere in the points A, B,and C. If these points are connected by arcs of great circles,they will form another spherical triangle ABC,…
Geometrical drawing
Internet Archive · Wellesley College Library · Public Domain Mark 1.0. Free to use for anything.
