THE GENERAL LINEAR GROUP 
301 
= R 
Fic. 33. 
358. Type I. 
A 
In the first case let the line AA’, Fig. 33, 
be the line at infinity and let the triangle PQR be trans- 
formed by 7” into P,Q,R,, Q and R being two points on Al’. 
The one-dimensional transformation along /’ is an Euclidian 
translation (Art. 108), and hence Q,R,= QR. 
ratio of the transformations of the pencil through A is 
ANU CALE EL \i— Ki (0 corprp) 
The cross- 
= ” where p and p, are the per- 
Pp 
c A Pi Qik, Pi 
pendiculars from Pand P, tol. Hence Rk = Maat eo =} 
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