Given that ABC is a right angled triangle
Such that,
∠A = 90°
And,
AB = AC
Since,
AB = AC
ΔABC is also isosceles triangle
Therefore, we can say that ΔABC is a right angled isosceles triangle.
∠C = ∠B
And,
∠A = 90°
Now, we have
Sum of angles in a triangle = 180°
∠A + ∠B + ∠C = 180°
90° + ∠B + ∠B = 180°(From i)
90° + 2∠B = 180°
2∠B = 90°
∠B = 45°
Therefore, ∠B = ∠C = 45°