2 cof. ] a' fin. B fin. G t- cof. A 4- cof. (B - C) 

 — 1 cof. -; (A f B - C) cof. -; (A - B + C),- 



- fio. ; fl' fin. B fin. C =: cof. A -\- cof. (B + C) 

 =: 2 cof K^. + B + C) cof. ; (B + C - A) ; 



Tbi fi breuitatis gratia ftatuatur ^ (A + B -f C) — S , erit 

 cof. ; a' fin. B fin. C — cof. (S - C) cof (S - B) i et 

 fin. \ a' fin. B fin. C = - cof. S . cof. (S - A), 



hincque colligitur 



fin ^ V— cor. S cof. (S - A) co f. (S - C) co(. (S — BJ 



2jza. B Jm. C * ' 



Tum vero quum fimili rafione fit:^ 



cof -' ^ r y <">('^^—^ )cof.(s- c) . ^p j ^ _ y__ cof. s. cor. ( g-B ; , 



'^ ~ Ji'!. A J;;i.C ' *= Jtn.\j{n.C "* 



COf.-C — i/ cu/.rs-A^oo/.cs- B)., r,, V-T/_w/^Sco/.rs-C) 



fiet 



fin. - C^ 4- ^^ — w/cg-Aj-f- cor. cs-B) y _ cof.^_eor. (s - o . 



cof i(a + b)zz: Cof-fs - o + co/. s) y . co/.(s- b) co/. fs - a) . 



et denique 



fin.i(«+HO = CcofS + cof.(S-C) + cof.(S-A) + cof.(S-B))Q, 

 exificnte 



Q — V- co/.s cor.(S - A) car.(S — B) co/. (S - C) 



Atqui efl: 



cof S + cof. (S - C) =1 2 cof -; C cof i (A + B) et 

 cof (S-A) + cor.(S-B) =: 2 cof; C cof.; (A-B) , 



qiiorum fumma erit 



I 3 2 (cof. 



