AO'.BF+BO'.AF-BF(AF'+FO)+AF(BF'+FO») 

 fiuc 



A O ' . B F + B O '. A F ir F ' . A B 4- B F. A F. A JB , 



vnde 



p 0» — LOLLL^o^ - A F. B F. Q. E. D. 



Continuatio prioris demonftrationis. 



Pona.tur A F = ~=^-^ = a , B G - tLpIJL — (3 , Tab. I. 

 efitqne- ' " \- - ^'^' '" 



a ff — a <r -I- r r dt ^ 5 ^ j3 f -f- r r.. 

 lam ex Lemrtrate errt 



cff- aa{c-a)-\-bb<x~(tc(c-a), - '^'^'^^^^ ^^ 



ct fi loco aa et ^ Z» (ubdituaninr valores modo aati, ha- 

 bebitur 



cff=crr-\-a^c, fiue //— rr r: a p. i' Qhkr 

 Cum porro fit ;> JT / ' /T/: 'C^ 



G O' = 5_o^Z:±:jio^ - AF. B F, 

 eodem modo demonftratur fore 



c ggzzzc r r -\- a^ Ci Cve gg — rr — a^ 

 hincqne 



ff-rr~gg-rr- ^±±::^I21^\=L1J:1, Q. E. D;^I 

 Hinc fequens formari poteft ^ ^''^ 



Theorema. 



Si ex trianguli ABC pundo O ad bafin AB duacFig. *, 

 ducantur redae inter fe aequales OF et OG, erit 

 A O* - A B. A F - B O^ - A B. B G. 



M 3 Demon- 



