PHYSICAL AND LITERARY. 107 



E in the curve, and drawCF paral- 

 lel to DE, meeting the curve in F ; 

 let EG, a tangent to the curve at E, 

 meet CF in G, and join DF, DG, 

 and let DG meet the curve in H ; 

 let the point D be between the 

 points, A, C : the feftor ACE will 

 be greater than the fe6lor ADH, 

 but lefs than the fedor ADF ; and 

 the feaor BCE will be greater than 

 the fe6lor BDF, but lefs than the 

 feaor BDH. 



Because the triangle DEC is greater than 

 the feflor EDH, let the fecftor ADE be added 

 to both ; and the fpace ACE will be greater 

 than the feftor ADH : and, becaufe the tri- 

 angle DEC is lefs than the feftor EDF, let 

 the feftor ADE be added to both ; and the fe- 

 aor ACE will be lefs than the fedlor ADF. 



Again, becaufe the fedtor ACE together 

 with the feaor BCE, is equal to the fedor 

 ADF together with the feftor BDF, and the 



fedlor 



