are points on the circumference of a circle with centre . Angle . What is the size of angle ?

Answer and explanation

Correct answer: C.

  1. Step 1: Identify the applicable circle theorem: the angle subtended by an arc at the centre is twice the angle subtended by it at any point on the circumference: .
  2. Step 2: Divide the central angle by : .
Answer
.
Why not the others: assumes central and circumference angles are equal; subtracts from ; is the supplementary angle in the major segment if lay on the reflex arc.

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