Question

In ∆ABC, AB = AC and ∠B = 45°. Then, ∠A is

1) 45°
2) 60°
3) 90°
4) 75°​

Answer 1

Answer:

The correct answer is B)90°

Answer 2

In ∆ABC, AB=AC, ∠B = 45°

It is isosceles triangle so ∠B =∠C

∠B =∠C= 45°

So, In ∆ABC,

∠A+∠B +∠C= 180°

∠A+45°+45°=180°

∠A+90°=180°

∠A= 180°-90°

∠A=90°

so, ∠A=90°