Circle theorems are properties that are true for all circles, regardless of their size. There are six theorems to learn and recognise. Questions can have a combination of theorems. It is important to ...

More simply, the angle at the centre is double the angle at the circumference. Angle OGK (\(x\)) = angle OKG because triangle GOK is also isosceles. Lengths OK and OG are also both radii. Angle GOH = ...