
In the diagram, O is the centre. If PQ//RS and ∠ONS = 140°, find the size of ∠POM.
The correct answer is: A
Explanation

In the diagram above,
∠MNO = 140° and angles on a straight line is 180°
: ∠NMO = (180 - 140)° = 40°
Hence; ∠POM = 40° ( alternate angle ∠S)