In the given figure OA and OB are opposite rays:
If x = 75∘, then what is the value of y in degrees?
Since ∠AOC and ∠BOC form a linear pair.
Therefore, ∠AOC + ∠BOC = 180∘
⇒ x + y =180∘ ........ (a)
If x = 75∘, then from (a) ;
⇒ 75∘ + y = 180∘
⇒ y = 105∘