Source$-$to$-$axis distance $($SAD$)=100\mathrm{.}0$ cm Depth $($d$)=7\mathrm{.}5$ cm Collimator jaw settings: X$1=7\mathrm{.}0$ cm X$2=5\mathrm{.}0$ cm Y$1=-2\mathrm{.}0$ cm Y$2=10\mathrm{.}0$ cm Based on the information above, What is the radius from the central axis to the center of the open field ?