Answer:
angle B is 38 degree
Step-by-step explanation:
In triangle ADC,
finding angle C
angle A + angle C = 110 degree (sum of two interior opposite angles are equal to the exterior angle formed)
46 + angle C = 110
angle C = 110 - 46
angle C = 64 degree
In triangle ABC
finding angle B
angle A + angle B + angle C = 180 degree (sum of interior angles of a triangle)
78 + angle B + 64 = 180
142 + angle B = 180
angle B = 180 - 142
angle B = 38 degree
