Answer:
116°
Explanation:
(Angle sum property of a triangle = 180°) 
 
angle A + angle C + angle ABC = 180° 
 
66° + 50° + angle BAC = 180° 
 
116° + angle ABC = 180° 
 
angle ABC = 180° - 116° 
 
angle ABC = 64° 
 
angle ABD + angle ABC = 180° 
 
angle ABD + 64° = 180° 
 
angle ABD = 180° - 64° 
 
angle ABD = 116° 
 
So, the measure of the unknown angle is 116°