Correct option is (2) 53
\(\mathrm{A}(\mathrm{a},-2), \mathrm{B}(\mathrm{a}, 6), \mathrm{C}\left(\frac{\mathrm{a}}{4},-2\right), \mathrm{O}\left(5, \frac{\mathrm{a}}{4}\right)\)
\(\mathrm{AO}=\mathrm{BO}\)
\((a-5)^{2}+\left(\frac{a}{4}+2\right)^{2}=(a-5)^{2}+\left(\frac{a}{4}-6\right)^{2}\)
\(\mathrm{a}=8\)
\(\mathrm{AB}=8, \mathrm{AC}=6, \mathrm{BC}=10\)
\(\alpha=5, \beta=24, \gamma=24\)