Ball, W. W. Rouse (Walter William Rouse), 1850-1925 · London, Macmillan · leaf 342
us of the proofsgiven by Legendre*. A triangle ABG is completely deter-mined by one side and two angles, say, a, B, G. Given these,the triangle can be constructed, and therefore the angle A de-termined. Now if the unit of length be changed the measure ♦ Elements de Geometrie, Paris, 12th edition,… … Now take a right-angled triangle DBF, of which D is theright angle. Draw DG perpendicular to EF. The angle EDGin the triangle EDG is calculated from the other two angles ofthat triangle, namely E and a right angle, in the same wayas the angle F in the triangle DEF is calculated from theother two…
Mathematical recreations · Geometry · Astrology · Space and time · Matter · Magic squares
Internet Archive · Public Domain Mark 1.0. Free to use for anything.
