ct Cc fmt inclinationes ad horixpntem , feu anguli 

 BAj — a, CB^nzp, DC<r — --Y, 



His pofitis erunt interualla 



Aa zza cof. « ; B ^ i= ^ cof. (3 ; C c ir f cof. y, 

 ct altitudines, feu perpendicula ex iunduris demifla 



B a — a fin. « ; C B — b (in. ^; D c— — cCin.y. 

 lam cum puiidtaActD funt data, ducatur vcrticalis D M, 

 voceturque diftantia A M := w cf altjtudo MD— », at- 

 que manifeftum eft forc 



m — a cof. a-\- b cof. (3 + ^ cof y et 

 » r: a fin. a -H ^ fia, (3 + <r fin. y 

 atque ex his duabus aequationibus, in quibus tam longitu- 

 dines trabium a, b, c^ quam interaialia m et n funt co- 

 gnita, trium angulorum a, p, y, duo determinantur: 

 tertius vero, cx conditione aequilibrii definiendus, adliuc 

 manet indefinitus. 



Tab. V. Refohiatur nunc vis dcorfum vrgens B P — P fc- 



^'S- 5« cundum dircdiones longitudinales trabium BA et BC; 



hunc in fincm faciatur Parallelogrammum P c^ B<^, ex quo 



colhgitur: BP: Bfl'=P: vim fec. BA 

 et BP: Bc' — ?: vim fcc. B C. 



Eft vero 

 BP: Ba'=zfin.Ba'?: fin. B P/i^ =- fin. AB C: fin. aBC 

 BP: Bf' =rfin.Bfl'P: fin. B Pc' — fin. A B Ct fio.flBA 

 Fig. 4.. vnde per angulos ad priorem figuram relatos crit 

 P : vim fec. B A = fin. A B C : fin. a B C 



P: vim fec. BCi^fin. ABC: fin. aBA 



ox 



