212 A MANUAL FOR NORTHERN WOODSMEN 



SOLUTION OF TRIANGLES 



The figure may refresh to good pur- 

 pose the memory of the field worker. 

 In it are graphically represented the 

 functions (sine, cosine, secant, and 

 tangent) of the angle BAC. The 

 cosine, cosecant, 

 /\ and cotangent of 



triangle A B C are as follows : 



BAC are respect- 

 ively the sine, 

 secant, and tangent of CAD, the 

 complement of BAC. 



Represented as ratios, the functions 

 of the angle A in the right-angled 





Tangent^ - 



By these formulas, and the use of the tables of sines and 

 tangents, all the parts of any right-angled triangle may be 

 obtained if two sides, or an acute angle and a side, are 

 given. 



All the parts and the area of an 

 oblique triangle may be obtained if 

 any three parts including one side 

 are given. Let A, B, C represent 

 the angles, and a, b, c the opposite 

 sides, of any oblique triangle ; then A , 

 the solutions are as given on the 

 next page. 



