2026 · Q52
Let O be the centre of a circle. Let A, B and C lie on the circle such that ∠ABC = 153°. What is the value of ∠AOC?
Elementary MathematicsCircles
- A54°
- B52°
- C39°
- D27°
Explanation
The inscribed angle ∠ABC=153° subtends the major arc AC of 2×153°=306°. The minor arc AC is 360°−306°=54°, and the central angle ∠AOC subtending it is 54°, option A. Doubling 153° without taking the minor arc gives the distractor 306°.