
Slope of diagonal OB =1−33+1∴=tan105∘∴α=60∘∴A(acos60∘,asin60∘)∴A(2a,23a)
A Lies on other diagonal
$\begin{aligned}
& \therefore\left(\frac{\sqrt{3}-1}{2}\right) a-\left(\frac{\sqrt{3}+1}{2}\right) \cdot \sqrt{3} a+8 \sqrt{3}=0 \
& a\left[\frac{\sqrt{3}-1-3-\sqrt{3}}{2}\right]=-8 \sqrt{3} \
& a=4 \sqrt{3} \
& \therefore a^2=48
\end{aligned}$