Forces in Equilibrium

 
1.3  Forces in Equilibrium
 
  Forces in equilibrium  
  An object is said to be in equilibrium of forces when the forces acting on it produce a zero resultant force.  
     
 
  Cosine rule  
 

\(a^2=b^2+c^2-2bc\cos A\)

\(b^2=a^2+c^2-2ab\cos B\)

\(c^2=a^2+b^2-2ab\cos C\)

 
     
 
  Sine rule  
  \(\dfrac{a}{\sin A}=\dfrac{b}{\sin B}=\dfrac{c}{\sin C}\)