In Fig. 12.58, what are the angles of depression from

In a triangle,

$\Rightarrow \angle A=180^{\circ}-\left(90^{\circ}+60^{\circ}\right)$

$\Rightarrow \angle A=180^{\circ}-150^{\circ} \quad$ We know that $\left[\angle A+\angle B+\angle C=180^{\circ}\right]$

$\Rightarrow \angle A=30^{\circ}$

Again,

In a triangle,

$\Rightarrow \angle O_{2}=180^{\circ}-\left(90^{\circ}+45^{\circ}\right)$

$\Rightarrow \angle O_{2}=180^{\circ}-135^{\circ}$

$\Rightarrow \angle O_{2}=45^{\circ}$

Hence the required angles are $30^{\circ}, 45^{\circ}$.