-»l4-2 ) P2 ( ^?§<- 



Simili rnodo erit 



fiue 



B?.Bb-bb-rr. 

 Eodem modo colligitur foic 



FP.F/-//-rr ct G l\ G g = g g - r r. 

 Sumtis igitur 



A F zz ?^-r^'-j: et B G = tLi^j:. 



c c ' 



demonrtrandiim cll forc 



//- r r — g g - r r — (jf ^ o t^ & - jir) ^ 



qiiem in fincm fcqucns Lcmnu in fiibfidium ciit vo- 

 candum. 



Lcmma. 



Tab. I. Si ex trianguli A O B puntflo O ad latcris oppofiti 



**&• *• AB punclum datum F ducatur rcda OF, ciit 



F O' = A oM» F -f - B o\ A P _ A F. B F. 



A B 



Dcmonflratio. 



Dcmiffo ex E in A B" pcrpcndiculo O IT crit 

 AO'i:=AnM-nO'r:(AF-i-Fn)'4-FO'-Fn', 



fiuc 



A O' z: A F' -H F O' -\- 2 A F. F n ; 



codcmquc modo crit 



B O* z^ B FM- F O' - a B F. F n. 

 Si prifT harum acquationum du(fla in B F ad altcram in 

 AF duiflam addatur, prodibit 



AO'. 



