Question

find the value of all angle in the given figure and find measure of a, b and c

Answer 1

In triangle ADC,

⇒ b=60o+70o

⇒ b = 130o

Now, in triangle ABD,

⇒ a+b+30o = 180o

⇒ a = 180o−30o - 130o

⇒ a = 20o

Also, 

∠ADC=∠BAD+∠ABD  .... Exterior angle property

⇒ c=30o+a

⇒ c=30o+20o

⇒ c=50o

Therefore,

a=20o, b=1300, c=50o