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 
BAC are respect¬ 
Vi 
/n 
V 
V 
<A 
V 
— \ 
-z. \ 
/ cos 
m 
er) 
triangle ABC are as follows: 
CB 
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 
Sine A = 
AC 
Cosine A = 
AB 
AC 
Tangent A = 
AB 
Secant A 
AC 
AB 
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 ^ 
the solutions are as given on the 
next page. 
