In a triangle △ABC, AB = AC and ∠A = 80°, then find B.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 50°.
In a triangle △ABC, AB = AC and ∠A = 80°
Since AB = AC, △ABC is an isosceles triangle which means base angles ∠B and ∠C are equal
Let, ∠B and ∠C be x
We know that,
The sum of all angles of the triangle is 180°
⇒ ∠A + ∠B + ∠C = 180°
⇒ 80° + x + x = 180°
⇒ 2x = 100°
⇒ x = 100°
Therefore,
∠B = 50°