Mathematics

The key is to use the Law of Sines combined with the angle constraint. Since $B - C = 90°$, you can express $B$ in terms of $C$, then apply the sine rule to relate the sides $b$ and $c$ to their opposite angles. This gives you an equation in $C$ alone, which you can solve to find the individual angles—and finally $A$ using $A + B + C = 180°$.

The key is to use the Law of Sines combined with the angle constraint. Since $B - C = 90°$, you can express $B$ in terms of $C$, then apply the sine rule to relate the sides $b$ and $c$ to their opposite angles. This gives you an equation in $C$ alone, which you can solve to find the individual angles—and finally $A$ using $A + B + C = 180°$.