"^^.i ) 344 C ^?§*- 



A C, Ac, B C, b c refpediue indicentur per a, a', b, -^', 

 c, c' et angiilus C A B per a, problema noftrum eo re- 

 ducirur vt ex datis, <7, «', b, b', et ^- colligatur c'. 



§. 3. Prima Methodus quae pro folutione huius 

 Problcmatis fe offert et rigori Geometrico plane confor- 

 mis eft, in eo confiftit, vt primum ex datis tribus latcri- 

 bus trianguli Sphaerici ACB inueftigetur angulus CABzr a, 

 tumque ex datis binis lateribus A b ~ a' , A c — b\ cum 

 angulo interiacente a. in triangulo Acb, quaeratur latus 

 b c zn c'. Pro hoc inftituto variae procedendi rationes ad- 

 hiberi pofTunt, vcrum hic non nifi praccipuas recencuifle 

 iuuabit. Quum itaque fit in triangulo A C B, 



cof. c — cof. a cof. b ■+ fin. b fin. a cof a , 

 colligitur 



r .cof. c — cof. a cof. b hinr- 



coi. 0. :Z— -^ — : — 7 — -, — 1 ninc 



I 4- cof a _ —jrn-kmT^ ^^ 



x—co^.ai — '-°L!^~~-:^^^^^^P^, vndc ii ponatur 



s = {{a-\-b-\-c), fiet 



cof r — cof ( rt + ^ ) — 2 fin. s fin. ( s — c) et 

 cof {a-b) — co(.c—i fin. [s- a) fin. [s - b ), 

 hincque obtincbimus 



tumque 



tang. : a' — ^Mlz-JLl^^ ^ -±) . 



§. 4. Porro quum fit 

 cof c' — cof i?' cof b* -+- fin. a' fin. b* cof a , 

 coUigitur 

 cof. c' — cof a' cof ^' +fin. fl'fin.^'— fin.fl'fin.^'( i — cof a.) 



— cof ( a' - b' )— 2. fin. a' fin. b' fn. .! a* 



. tumaue 



