Let A (1,2) and C (-3,-6) be two diagonally opposite vertices of a rhombus, whose sides AD and BC are parallel to the line 7 x-y=14. If B (α, β) and…

Let $\displaystyle \mathrm{A}(1,2)$ and $\displaystyle \mathrm{C}(-3,-6)$ be two diagonally opposite vertices of a rhombus, whose sides AD and BC are parallel to the line $\displaystyle 7 x-y=14$. If $\displaystyle \mathrm{B}(\alpha, \beta)$ and $\displaystyle \mathrm{D}(\gamma, \delta)$ are the other two vertices, then $\displaystyle |\alpha+\beta+\gamma+\delta|$ is equal to