text: # AB and CD are two equal chords of a circle with centre O such that ∠AOB = 80°, then ∠COD = ?
  
  Question:
  
  AB and CD are two equal chords of a circle with centre O such that AOB = 80°, then ∠COD = ?
  (a) 100°
  (b) 80°
  (c) 120°
  (d) 40°
  
  Solution:
  
  (b) 80°
  Given: AB = CD
  We know that equal chords of a circle subtend equal angles at the centre.
  ∴ ∠COD = ∠AOB = 80°