Legendre, A. M. (Adrien Marie), 1752-1833, Brewster, David, Sir, 1781-1868, Davies, Charles, 1798-1876 · New York, Wiley & Long · leaf 97
ve theproportion AD : CI : : BD : BC ; hence AD.BC^CI.BDAgain, the triangle ABl is similar to the triangle BDC ; for thearc AD being equal to CO, if OD be added to each of them,we shall have the arc AO=:DC ; hence the angle ABI is.equalto DBC ; also the angle BAI to BDC, because they are in-scribed… … AI.BD + CI.BD =^ (AI + CI).BD=AC.BD, we «hall have AD.BC + AB.CD=AC.Ba 113 M GEOMETRY.
Trigonometry · Geometry
Internet Archive · Wellesley College Library · Public Domain Mark 1.0. Free to use for anything.
