Answer the following questions with reference to a circle having centre O and a chord AB.
a. (i) Define the term “distance of a chord from the centre” of a circle.
b. (ii) If the distance of chord AB from O is equal to the distance of another chord CD from O, what relation can you state between the lengths of AB and CD? Give reason.
c. (iii) Let M be the midpoint of AB. Describe, with reason, the nature of △OMB. What is the measure of ∠OMB?