Let R be the focus of the parabola y^2=20 x and the line y=m x+c intersect the parabola at two points P and Q. Let the point G(10,10) be the centroid…

Let $\displaystyle R$ be the focus of the parabola $\displaystyle y^2=20 x$ and the line $\displaystyle y=m x+c$ intersect the parabola at two points $\displaystyle P$ and $\displaystyle Q$. Let the point $\displaystyle G(10,10)$ be the centroid of the triangle $\displaystyle P Q R$. If $\displaystyle c-m=6$, then $\displaystyle (P Q)^2$ is