Circle theorems: chords and tangents

Use theorems about chords and tangents, such as a tangent meeting the radius at 90°, to solve problems with reasons.

⏱ 20 min❓ 10 questions

What you'll be able to do

✔I can use the fact that the perpendicular from the centre bisects a chord
✔I can use the tangent–radius and equal-tangent theorems with Pythagoras
✔I can apply the alternate segment theorem to find unknown angles

How this works

1Read the short explanations first — they teach you what you need before each question.
2Answer each question, then tap Check. A right answer moves you on automatically; if it's wrong, you'll see a friendly explanation of why.
3Finish all 3 steps to see your score — sign in and subscribe to unlock the full lesson and save it.

What's inside

10 questions and 1 quick teaching card, including:

🔘Multiple choice — Tap the answer you think is best, then check it.
🔢Number answer — Work out the answer and type the number.

👪Grown-up tip: sit alongside younger learners for the first few lessons. Read the questions together and chat about the explanations — that's where the real learning sticks.

Curriculum: AC9M10SP01