2020 · Q69
Two circles of radii 20 cm and 16 cm intersect and the length of common chord is 24 cm. If d is the distance between their centres, then which one of the following is correct?
Elementary MathematicsCircles
- Ad < 26 cm
- B26 cm < d < 27 cm
- C27 cm < d < 28 cm
- Dd > 28 cm
Explanation
The half-chord is 12 cm. Distances of the chord from the centres are √(20² − 12²) = 16 and √(16² − 12²) = 4√7 ≈ 10.58. The centre distance is 16 + 4√7 ≈ 26.58, between 26 and 27 cm.