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 ? |
52° 48° 56° 60° |
56° |
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° |