Points lie consecutively on a circle, forming a cyclic quadrilateral. Angle and angle . Find the value of .

Answer and explanation

Correct answer: B.

  1. Step 1: Apply the circle theorem for cyclic quadrilaterals: opposite angles in a cyclic quadrilateral sum to : .
  2. Step 2: Form the linear equation: .
  3. Step 3: Solve for : .
Answer
.
Why not the others: subtracts to get and divides by 4; equates the two opposite angles (); mistakenly equates opposite angles.

Practise more Geometry, Trigonometry and Circle Theorems.

Free questions with an explanation for every one, and full timed UK GCSE mock tests.