Question

If chords AB and CD of congruent circles subtend equal angles at their centres, then which of the option is correct?

• A.
  $AB=CD$
• B.
  $AB>CD$
• C.
  $AB<CD$
• D.
  None of the above

Answer 1

The correct option is A

$AB=CD$
In triangles AOB and COD,

$\angle AOB=\angle COD\left(Given\right)OA=OCandOB=OD\text{(radii of the circle)}So,\Delta AOB\cong \Delta COD.\text{(SAS congruency)}\therefore AB=CD\left(ByCPCT\right)$

Hence, the correct option is (a)