The idea
Angles around a point total 360°.

Follow these steps
- Add all known angles around the point.
- Represent equal unknown angles consistently.
- Subtract from 360° and divide if more than one equal angle remains.
See the method in action
Example 1
The smaller angle is labelled. What is the reflex angle between the same two rays?
Not drawn to scale
- The two angles made by the rays complete a full turn.
- Therefore the reflex angle is 360° − 138° = 222°.
Example 2
The smaller angle is labelled. What is the reflex angle between the same two rays?
Not drawn to scale
- The two angles made by the rays complete a full turn.
- Therefore the reflex angle is 360° − 138° = 222°.
A useful shortcut
Subtract from 360° and divide if more than one equal angle remains.
Watch out for these
Three fresh questions
Ready to check the method? You will get three fresh, validated questions.