English

Noun

umbra recta sg

1. On a shadow in the shape of a right triangle, the length of the shadow's edge adjacent to a measured angle.
   • 1688, John Hales, “The Rich man’s Recepiſti” in Golden Remains (3rd ed.), page 77

     Scheubelius a great Mathematician, but by book only, and not by practice who being required ſometime in an Army to make uſe of his Quadrant, knew not the difference between umbra recta, and umbra verſa.

Synonyms

• umbra extensa