In ΔABC, D is a point on side BC such that ∠ADC = 2 ∠BAD. If ∠A = 70° and ∠C = 48°, then what is the measure of ∠ADB ?
Answer & explanation
Correct answer: option 3
In ΔABC
∠A + ∠B + ∠C = 180°
70° + ∠B + 48° = 180°
∠B = 180° - 118° = 62°
∠ADC = ∠BAD + ∠ABD
2θ = θ + 62°
θ = 62°
∠ADB = 180° - ∠ADC = 180° - 2θ = 180° - 124° = 56°