\[
\left[ {\begin{array}{ccc}
1/9 & 1/9 & 1/9
1/9 & 1/9 & 1/9
1/9 & 1/9 & 1/9
\end{array} } \right]
\]
\[
\left[ {\begin{array}{ccc}
1/16 & 1/16 & 1/16
1/16 & 1/2 & 1/16
1/16 & 1/16 & 1/16
\end{array} } \right]
\]
\[ \theta_2 = \tan ^{-1}\left(\frac{\frac{50 pixels}{72 pixels}}{.5}\right) = 54.24^{\circ} \] \[ \theta_1 = \tan ^{-1}\left(\frac{\frac{30 pixels}{72 pixels}}{.5}\right) = 39.8^{\circ} \]
\[ L = 90^{\circ} - \theta_1 = 50.194^{\circ} \]
\[ R = 90^{\circ} - \theta_2 = 35.7556^{\circ} \]
\[ \tan(R) = \frac{d}{12.5 + r}; \tan(L) = \frac{d}{r} \]
\[ \tan(R)*(12.5 + r) = \tan(L)*r \Rightarrow r = \frac{12.5}{\tan(L) - \tan(R)} = 18.75 \]
\[ d = \tan(R)*(12.5 + r) = 22.5 \]