SCIENCE ABSOLUTE OF SPACE. 



BNiiES, and (since DT II CG) BQllET; con 

 sequently (#1) ZEBN-ZEBQ. Let BCF be 

 an L-liiu of HX. and KG, I)H, CK, EL, L form 

 linrs of FT, DT, CQ and ET; evidently ($22) 

 II G =DF=DK=HC; therefore, 



Likewise it is evident BG 21&amp;gt;L 2-~. 



But BC-BG-CG; wherefore y=z-v, and 



so ( _ 



Finally (28) 



Z = l : sin y 2 it. 

 and V = l : sin (rt.^ ]/2 u], 

 consequently Y cotan y 2 u. 



$30. However, it is easy to see (by 25) (is) 

 that the solution of the problem of Plane 

 Trigonometry, in S, requires 

 the expression of the circle 

 in terms of the radius; but 

 this ran by obtained by the 

 rectification of L. 



Let AB, CM, C M be 

 rav AC, and B anywhere in 

 ray AB; we shall have ($25) 



sin // : sin V= 

 and sin // : sin v =Q 



and so 



sin r 



sin v 



