Question:
In ∆ABC, if ∠B = 76° and ∠C = 48°, find ∠A.
Solution:
In $\Delta A B C$,
$\angle A+\angle B+\angle C=180^{\circ} \quad$ [Sum of the angles of a triangle]
$\Rightarrow \angle A+76^{\circ}+48^{\circ}=180^{\circ}$
$\Rightarrow \angle A+124^{\circ}=180^{\circ}$
$\Rightarrow \angle A=56^{\circ}$