39 



in the direction of the ground to be surveyed, station 

 poles should be set up for guides. 



The following directions will enable an inexperienced 

 surveyor to ascertain the contents of most figures: 



1. To find the area of a K 

 parallelogram A B D C :- ,L\- 



Multiply its length A B by its perpendicular height A E. 



Example Required the contents of a field, whose op- 

 posite sides are parallel ; the length of its base being 

 10*36, and its perpendicular height 5'40. 



10-36 

 5-40 



41440 

 5180 



5-59440 

 4 



15-10400 



Ans. 



A. R. P. 



5 2 15 



2. To find the area of a triangle 

 ABC: 



Multiply the base AC by the perpen- 

 dicular B D, and take half the product; 

 or multiply the base by half the per- A , 

 pendicular. 



Example Required the contents of a triangular field, 

 whose base is 12'56, and its perpendicular height 8'50. 



12-56 

 4-25 half the perpendicular. 



1-35200 

 40 



A. R. P. 



14-08000 AllS. 5 1 14 



