=^i . ' ^numerical InflruSiions 



the Content is 198 Foot, i Inch, and 6 Parts 5 

 but thefe Parts we generally throw away, ex- 

 cept in fine Wbrks. 



Of Triangles^ (Fig, 3, Plate 23.J . 



: f The Content of a Triangle is known by 

 multiplying half the Perpendicular by the 

 whole Bafe, or, e contra^ half the Bafe by 

 the whole Perpendicular 5 but the Dimenfions 

 are taken as the Nature of the Triangle is ^ 

 and thofe three Kinds, in Fig. 6, give Light 

 thereinto, being fuch as all Sorts of Triangles 

 compofe. 



When you have,then,pitch'd upon the Bafe, 

 (which in every one of thefe is A at Right 

 Angles) thereto draw or fuppofe a prick'd 

 Line to run up to the Angle oppofite to it^ 

 and that is the Perpendicular. 



See the calling up of one of them. 



In the firft Triangle, the Bafe c d is 22 

 Chains, 50 Links 5 and the Perpendicul^. ^ ^e 

 is 2 Chains 50 Links. $ee. it ftated. , i 



I-; V 



