OES AN ACCOUNT OF THE 
‘known sides of the triangles are always on the third or last line. The 
heading of the columns is sufficiently intelligible. Some triangles are 
resolved by cosines, for instance, when 2 sides and 3 angles are given, 
those angles being very acute, that is less than 30. In resolving 4 sided 
figures, the general method that has been followed is to draw parallels 
to the 2 unknown sides—by which means 2 triangles are obtained, 
in which all 3 angles are given, and one side. In resolving a 5 or 6 
sided figure I have preferred, letting fall perpendiculars, from each of 
the angular points on the unknown side, and calculating the several sides: 
or pieces, intercepted by these perpendiculars. But from the paper itself 
it will be sufficiently clear, how each result is obtained, and from the 
full detail that is given, it will be an easy task to detect any mistakes 
that may have been made. | 
