s^ 



^ 



ASTRONOMICAL and 



as, B. 



S. 69° 43' WAB.;— AI— KB 



o 



N. jj E. BC 



KM 



' BK+MC 



LM 



aCxM 



NE, SW. 

 2 0FLM(=MLXKMby Lem. j.) 



2DEQR (:=2 DR+T Exl> T bjr 



Lem. I.) 



NW,SE. 



S. 43 W. CD 



CN 



4 CM— CN 

 NDl a DR 





N. 64 E. DE 

 DT 



TE 

 a DR +TE 

 aEC^ 



2 CDRM (zisCM—G NxND by 



L 



Lem. 2.) 



by 



S. 24 W. EL;\ 



a EC^EP 



?A' Al+KB 



2 EAI Q (=2 E Q— E PxP 

 Lem. 2.) 



OFLM4-DEQR— CDRM 



ABCDE. 



EA t 



DEMONSTRATIOli. 



I 



OFLM-J-FCL=aCM. 

 OCM— CDRM^OCDR. 



OCDR+DEQR=:OCDE(2. 



OCDEQ— EAIQ=OCDEAL 



OCDE AlrrOCDEABK 

 OCBEABK— BOK=ABCDE. 



t* ^ 



Hence by fvibftkution 



O F L M— C D R M+D E Q R 



Q. E» D. 



EAI 



ABCDE 



EXAMPLE 



