2l8 



A =: 



sm. — 



B rz 



n — 2 



-4- i -H 



C =: ^ 



À sin. 



quorum valorum numerus cum sit n — 1, eorum summa ent 

 ll!L-_l) _ I ( 1 + 2 + 3 -+. 4 4- . . . (« - 1 )) + "-^ 



1 - - - ' - (2P.-3)-7r -| 



4 sin. — 

 n 



(2rt — m) TT 



T [sin- Y + sm. — 4- sin. — -f- . . . sin. — ,^ J. 



• TTITT 



sm. -- , ergo 



Est - vero sin. 



Sin. - 4- sm. -^ + sm. ^ -4- . . . sm. -^ ;^— — sm. - ^ 



unde igitur colligitur fore 



B 



. M = 



consequenter 



AB- 4- AC" 4- AD' + AE' 4- 



4- BC' 4- BD= 4- BE' -h 



4- CD' + CE' 4- 



4-DE'4- 



4- 



AN' ] 

 BN^ I 

 CN' \ 



DN' 



4-MN' 



l 



=z nn AO'. 



J 



Th e o r em a III . 



§.10, In omni Polycjono regulari , si ex circuli circumscripti 



puncto quolibet Y ad angulos A, B,C, A'" rectae eclu- 



cantur , summa quadratorum haruui lectaruin aequatur 



l 



