Question

pls tell me question no

Answer 1

Let ABC be a triangle whose side C has been produced to D.
Angle ACD = 100 (exterior angle)
Angle ACB = 180 - 100 (linear pair)
ACB = 80

ACB + ABC + BAC = 180
80 + ABC + BAC = 180
ABC + BAC = 100
2ABC = 100
ABC = 100/2 = 50
BAC = ABC = 50