iig DE RESOLVTIONE 



nes fint fufcipi^ndae, obferuationes quasdam circa ae- 

 quationes pro Pentagono locum habentes lieic adfere- 

 mus , qutbus pcrpenfis non (olum qiiaeftiones pro 

 Pentflgono facile folu^^ntur , fed via quoque praepa- 

 retur ad (olu-tiones aliorum Polygoiorum exfequen- 

 das. Pro Peutagono autem iequcntes habemus ae- 

 quationes : 



I. cc — a-^-b^-hc^+^^+^abcof.B + aacccC (B + C) 

 4- 2 fl dcoi. ( B + C + D} + 2 bccol. C+ 2 ^^coC (C-f-])) 

 -{-zcdcof. D 



II. ee-i- zedcoi. E-^-dd—aa-^-bb-hcc+a.abcoC.B 



-+- 2 a c coL(B -\-C)+ 2 b c coi.C 

 m. a fm. A + ^ Cn. ( A 4- B ) -h ^ fin. ( A + B 4- C ) 



+ d fm. (A + B+C + D)— o 



IV. rtfin.A + ^fin.^A + B^+c^fin.CA + BiCj-fl^fin.Ero 



V. rtfin.A + ^.fin.(A + B)-tfin.(D+E)-</fin.E=o. 

 De tribus pofieribus fiue ex iis latera , feu anguli 

 detcrminari debent , vix quicquam monere nectiTe 

 cd i fiquidem huiusmodi detcrminatio facillima cfi , 

 nec complicatiores reqivrit opcrationcs , quam qui- 

 bus ia paribus cafibus pro quadrilatcro \C\ fumus. 

 De prima autem aequatione fi ex ea nhquod late- 

 rum , vtpote ^, vlI a, vcl b, dcterminandum fit 

 notare iuuat, quod fub his formis commodc cxpri- 

 mi queat *. 



I. ^crr;rt+^7corB + <rcof(B + C) + ^cof.(B + C+D))= 



+ (^0n.B4ffin.(B + C) + ^fin.(B + C+l)))= 



a. ee — {b-{-a cof. B + c cof C -+ r/ cof. ( C -f- D ))' 



H- ( a fin. B - c fin. C ^ ^ fin. ( C H- D ) )*. 



Liquct 



