(i) In Figure (1), O is the centre of the circle. If ∠OAB=40∘ and ∠OCB=30∘, find ∠AOC.
(ii) In Figure (2), A, B and C are three points on the circle with centre O such that ∠AOB=90∘ and ∠AOC=110∘. Find ∠BAC.
In the given figure, if ∠AOC and ∠BOC are in ratio 2 : 3, find ∠AOC, ∠COB, ∠BOD and ∠AOD.
From the figure given below, find out the measure of ∠COB and ∠AOC respectively.