Angles around a point: finding the missing angle
22 October 2026
Angles around a point can look tricky at first, but there is a simple rule that helps every time. If you know most of the angles, you can always work out the one that is missing.
Worked example
Four angles meet at a point. Three angles are 90°, 120°, and 75°. What is the fourth angle?
Step 1: All angles around a point add up to 360°.
Step 2: Add the known angles: 90 + 120 + 75 = 285°.
Step 3: Subtract this sum from 360 to find the missing angle: 360 - 285 = 75°.
The correct answer is 75°.
Angle chart
Around a point · 360°Key insight: Once your child understands that all angles around a point add up to 360°, they can spot missing angles quickly. This skill is important for many 11+ questions, and there are more practice problems just like this to help them get confident.
