Wentworth, G. A. (George Albert), 1835-1906 · Boston, Ginn & company · leaf 116
RIANGLE. 107 [41] whence, sin b = tan a cot A and, similarly, sin a = tan b cot B If in [37] we substitute for cos a and cos b their values from[40], we obtain cos c = cot A cot B. [42] In deducing these formulas, it has been assumed that allthe parts of the triangle, except the right angle, are… … Fig. 37. The auxiliary plane BBE will now cut both CO and AOproduced beyond the centre 0; and we have cos(180 -c) = OE=OBxcosb = cos(180 - a) cosb,a result which reduces to [37] if we substitute — cose in placeof cos(180 — c) and —cosa in place of cos(180 —a). Like-wise, the other formulas,…
Trigonometry · Surveying · Navigation
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
