Angles & Shapes
Angles always add to the same totals — use them to find missing ones.
Angles in a triangleAngles in quadrilateralsAngles on a line & at a pointVertically opposite anglesParts of a circle
📖 Learn
Totals
Straight line 180°, around a point 360°, triangle 180°, quadrilateral 360°.
Opposite angles
Where two lines cross, opposite angles are equal.
Circles
The diameter is twice the radius.
Worked example
A triangle has angles 50° and 70°. Find the third.
- 150 + 70 = 120
- 2180 − 120 = 60° ✅
🧪 Play with it: Angle turner
60° Acute
⭐ Practise
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