In the given figure, AB = AC. Angle BAC = 50 degrees. What is the value (in degrees) of angle ACD?
Show answer & explanation
Correct answer: B
Explanation
Given:
AB = AC
∠BAC = 50°
According to the formulas:
In an isosceles triangle, the base angles are equal.
The sum of the three angles of a triangle = 180°.
Exterior angle = 180° − Interior angle.
∠ABC = ∠ACB
∠ABC + ∠ACB + ∠BAC = 180°
2∠ACB + 50 = 180
2∠ACB = 130
∠ACB = 65°
∠ACD = 180 − 65
= 115°