Answer:
m∠B = 64°
Explanation:
We are told that m∠A = 50° and m∠ACD = 114°. We are then asked to find m∠B.
From the diagram, we can see the angles ACD and ACB lie on a straight line. Therefore, their measures add up to 180°. Hence:
∠ACD + ∠ACB = 180°
⇒ 114° + ∠ACB = 180°
⇒ ∠ACB = 180° - 114°
⇒ ∠ACB = 66°
∴ m∠C = 66°
We know that the angles inside a triangle add up to 180°.
Now that we know the measures of ∠A and ∠C, we can calculate m∠B:
∠A + ∠B + ∠C = 180°
⇒ 50° + ∠B + 66° = 180°
⇒ ∠B = 180° - 66° - 50°
⇒ ∠B = 64°