G2.1 Find the value of $2 \times \tan 1^{\circ} \times \tan 2^{\circ} \times \tan 3^{\circ} \times \ldots \times \tan 87^{\circ} \times \tan 88^{\circ} \times \tan 89^{\circ}$.
$\tan \theta \times \tan \left(90^{\circ}-\theta\right)=1$ for $\theta=1^{\circ}, 2^{\circ}, \ldots .44^{\circ}$ and $\tan 45^{\circ}=1$
$2 \times \tan 1^{\circ} \times \tan 2^{\circ} \times \tan 3^{\circ} \times \ldots \times \tan 87^{\circ} \times \tan 88^{\circ} \times \tan 89^{\circ}=2$