SPHAERICO - ASTRONOMICVM. 107 



ct cofinus — ;::. Iiidc porro habetur cofmus an^^u- 

 li EPG="^^" et cofiuus anguli EPF-^-^^ 



In tri;ingulis TAE, GAK et FAE anguli ;id A 

 dati lunt, fubtendunt enim complenienr.i altitudi' 

 num ZB, ZC ct ZD, quibus igitur lcniifribus acqiKin- 

 cur. Sit anguli TAE cofinus» —^, anguli GAE co- 

 finus ZZ.& et anguli FAEzzi-. 



Quoniam latera ET, EG et EF, tam ad trian- 

 gula in plano ( EPT, EPG, EPF ) quam ad triangiila 

 projectoria TAE, GAE et FAE pertiiKut , pote- 

 runt illa bis detcrminari et fic aequationcs formari 

 \ti fcquitur: 



I - - KYL^^-te-^^-^-aa-S^ 



3 - - Jir — — — fg— Pj3 — -^rT — —ot,a—do 



auferutur fecunda a prima et ficc 

 4. - - r(a-lf]e(i—(ry-}]j^nix)a$ 

 ct tcrtia a prima 



5 - - r(a-c)£(iz=:(ry-gj-{-fv)<x^ 



ex quarra et qiiinta fit 



6 ' ~ ry—n y-i-mx ry—g y^fx 



I a — 6 — a — c 



quae debitc rcdu(fla reddit tandcm 



1. . _ ££ (fl — b ■ r — f ' — 'a —c^^r— n) 



' y — («—6.7— a—c,m ~' 



2 Hac 



