In a ∆ABC, if AB=AC and ∠B=65°, find ∠A.
It is given in the question that,
In triangle ABC, AB = AC
∠B = 65°
As ABC is an isosceles triangle
∴ ∠C = ∠B
∠C = 65°
Now, we now that sum of all angles of a triangle is 180o
∴ ∠A + ∠B + ∠C = 180°
∠A + 65° + 65° = 180°
∠A + 130° = 180°
∠A = 180° – 130°
∠A = 50°