ideoque 



iSC-VOB-POV— iso^-VOB-PVO 

 — PVN4-VB0, 

 addatur vtrinque angiilus BVO, eritque 



i8o°+BVO-VOB-PVOrBVO + VBO f PVN, 

 vnde ob 



PVN = PVO-VNO=zPVO-AVB, ficti 

 iSo^ + BVO-VOB-PVO-BVO 



-hVBO + PVO-AVB, vnde 

 55o°-2POV:r:BV04-VBO-f-BOV, 



quum igitur fit angulus 



VOX = po°-POV, erit iSo^-aPO V= 2 VOX , 

 hincque 



i8o^-H2VOXz=BV04-VBO-l-BOV, 



ex quo iam conftat triangulum fphaericum B V O aequari 

 fegmento fphaerae AVOXA, hincque demto vtrinque 

 triangulo communi V O X, fiet triangulum AVXrBOX 

 et addito dcnuo vtrinque triangulo AXB fiet fegmentuin 

 AXOBA-AAVB. 



§. II. Si in fuperficie fphaerae trla fumantur 

 pun(fla A , B , V patet femper bina quaccunque corum , 

 duobus arcubus circulorum maximorum iungi pofTe , vno 

 fcilicet arcu femiciiculo minori, altero tantundem maiore 

 cxiflentej hincque fi per triangulum fphaericum, intelligii- 

 tur figura, quae includitur tribus arcubus circulorum maxi- 

 moium , patet iungendo tria puntfta A, B, V omnino 0(flo 



for- 



