The adjacent figure is the part of a horizontally stretched net. section AB is stretched with a force of 10 N. The tensions in the sections BC and BF are
 

By drawing the free body diagram of point B Let the tension in the section BC and BF are T₁ and T₂ respectively.
From Lami's theorem

$\frac{{\mathrm{T}}_1}{\sin 120°}=\frac{{\mathrm{T}}_2}{\sin 120°}=\frac{\mathrm{T}}{\sin 120°}$
$\Rightarrow \mathrm{T}={\mathrm{T}}_1={\mathrm{T}}_2=10\mathrm{N}.$