Question

In the given figure, angle ACB=40° and angle DAB=60°, find the measure of angle DBA.

Answer 1

angle ACB = angle ADB (angle in the same segment are equal)
Therefore, angle ADB = 40° ( Since angle ACB = 40°)
   Now,in Triangle ABD,
     angle ABD + angle ADB + angle DAB = 180° (Angle Sum Property)
    angle ABD + 40° + 60° = 180°
    angle ABD + 100° = 180°
    Thus, angle ABD = 180° - 100°
                 angle ABD = 80°

Hope it helps.......... :)