Let A and B be two distinct points on the line L: (x-6)/3=(y-7)/2=(z-7)/-2. Both A and B are at a distance 2 √ 17 from the foot of perpendicular…

Let $\displaystyle A$ and $\displaystyle B$ be two distinct points on the line $\displaystyle L: \frac{x-6}{3}=\frac{y-7}{2}=\frac{z-7}{-2}$. Both $\displaystyle A$ and $\displaystyle B$ are at a distance $\displaystyle 2 \sqrt{17}$ from the foot of perpendicular drawn from the point $\displaystyle (1,2,3)$ on the line $\displaystyle L$. If $\displaystyle O$ is the origin, then $\displaystyle \overrightarrow{O A} \cdot \overrightarrow{O B}$ is equal to