MA THEM A TICS 



FRUSTUM OF PRISM 



If a section perpendicular to the edges is a triangle, 

 square, parallelogram, or regular polygon, 



sum of lengths of edges 



V = X area of right section 



number of edges 



TRIGONOMETRY 



Trigonometry is that branch of mathematics which treats 

 of the properties of angular functions and their application 

 to the solution of triangles. The angular functions are certain 

 quantities, or ratios, depending 

 on the magnitude of an angle, 

 and serve for the determina- 

 tion of angles. There are six 

 angular functions; namely, the 

 sine, cosine, tangent, cotangent, 

 secant, and cosecant. If, in any 

 acute angle MAN, Fig. 1, 

 a perpendicular BC be drawn 

 to A N from any point on the 



bide adjacent** b 

 FlG. 1 



side AM, forming the right triangle ABC, its three sides are 

 named, with reference to the angle A, as follows: The side 

 AB = c, the hypotenuse; the side AC = b, the side adjacent; and 

 the side BC = a, the side opposite. The angular functions are 

 then defined as follows: 



side opposite a 



sin A = 



cos A 



tanA = 



cot A 



sec A = 



esc A 



hypotenuse c 



side adjacent b 



hypotenuse c 



side opposite a 



side adjacent b 



side adjacent b 1 



side opposite a tan A 



hypotenuse c 1 



side adjacent b cos A 



hypotenuse c 1 



side opposite a sin A 



