51^ Inflrumental InflruEiiom 



To find the Content of this Field. 



*^f,As in Trapezia we multiply half the 

 Bafe by the Sum of the two Perpendiculars, 

 fo in Triangles, F D E, we multiply the 

 Bafe F D by the Perpendicular E K, and 

 take half the Produft for its fuperficial Con- 

 ten t. 



Here note, that, where a Field confifts of 

 two or more Trapezia, and Triangles, you 

 muft make a feparate Work for each, and the 

 Sum of thofe Operations will be the Content 

 of the Field. 



See the Work of the Field before us : 



Trapezium-Bafe B F 5 lo p^^^fs 87 AO 



— *^^'H, 85 ca 



T 2 55 ^ 



4 72 

 2 55 



2360 

 2360 

 944 



Acre 1)20360 

 4 



Roods 0)81440 

 40 



Perches 32)57600 



Triangle 



