Coordinates of G1=\left(\frac{x_{1}+x_{2}}{2},\frac{y_{1}+y_{2}}{2}\right)
Coordinates of G2=\left(\frac{2\times\frac{x_{1}+x_{2}}{2}+x_{3}}{3},\frac{2\times\frac{y_{1}+y_{2}}{2}+y_{3}}{3}\right)=\left(\frac{x_{1}+x_{2}+x_{3}}{3},\frac{y_{1}+y_{2}+y_{3}}{3}\right)
Proceeding in this manner,Gn-1 turns out to be
\left(\frac{x_{1}+x_{2}+x_{3}+\cdots +x_{n}}{n},\frac{y_{1}+y_{2}+y_{3}+\cdots +y_{n}}{n}\right)