Question 22
Circle TheoremsIn the diagram below, O is the centre of the circle. Calculate the length of the chord AB if |OA| = 5cm, |OD| = 3cm and ∠AOD = ∠BOD.
- A.3cm
- B.4cm
- C.5cm
- D.8cm
- E.15cm
Show the answer and explanation
Answer: D (8cm)
Explanation
OD bisects the chord at right angles, so |AD| = √(5² − 3²) = 4 cm and |AB| = 2 × 4 = 8 cm.