Thursday 1 November 2012

TRIGONOMETRY : Properties of Triangles


Properties of Triangles

Consider a triangle has three angles A,B and C.The sides opposite to the angles A,B,C are denoted by the corresponding small letters a,b,c respectively.
Thus a=BC,b=CA,c=AB in the fig. shown below.

Sine Formula

 a/sina  = b/sinB=c/sinc=2R  Where R,is a Radius of Circle circum circle of the triangle.

Napier's Formulae :


Cosine Formulae:

  1. a2=b2+c2 -2bc cosA
  2. b2=c2+a2 -2ca cosB
  3. c2=a2+b2 -2ab cosC
Projection Formulae : 
  1. a =bcosC+ccosB
  2. b=ccosA+acosC
  3. c=acosB+bcosA
 Half Angle Formulae :


Area Formulae:


Post a Comment

Related Posts Plugin for WordPress, Blogger...