Question

Given: obtuse triangle ABC with obtuse angle B. Point D on side AC such that angle BDC is also obtuse. Angle DAB is 2/3 of angle ABD. Angle BCD is 1/5 angle BDC and angle CBD is 4 more than angle BAD. What is the measure of angle ABC?

Answer 1

½ m ےABC =½ m ےPQR