*-¥.^ ) 75 ( S-fC- 



Demonjir. Duftis arcubus circulorum maximorum A C, 

 B C, D C liquet angulos B A D, A B D, B D A per hos 

 arcus bifecari, vnde conflat elTe AEcrAGi BE — BF; 

 DG— -DF, quamobrem patet efle 



A E = 1 (A B H- B D ^- A D) - B D = j - ^; 



BE — :f-^i DY — s-c. 



lam in triangiilo AEC redangulo eft tang. A C E - ^J^I^^, 

 et in triangulo B E C, 



tang.BCE-g|^^, Iiinc 



^ I - tang. A C E tang. B C E 

 tang. A E -h tang, B E 



"" fin. E C (j -^-^MiJLl^iJLij* 



\ jm. t C I 



At quum fit angulus 



ACB-BCF+ ACG, 

 fiet omnino 



ACB — xso^-^FCGzziso^-FCD, 

 vnde 



tang. A C B =: - tang. F C D -- '-^_^ 



erit ergo haec aequatio: 



tang. A E H- tang. B E _ _ tang. F 



iin. c h [x^^^^MnjjEhij: — ii^cir' 



ex qua colligitur 



tang. A E H- tane. B E + tang. F D zr t°^g-AE;f£^E^T»g^FP ^ 



fong. A 'EH -ffJng.BE + Mng.FD -f- i 



ta/ig. A£ /arig. Bii Jan^/F D J/n.CE * 



hinc autem deducitur 



K 2 Ha. 



