GlossariesIGCSE GlossariesIGCSE Maths GlossaryIntersecting Chord Theorem

Intersecting Chord Theorem - IGCSE Maths Definition

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What is the intersecting chord theorem in IGCSE maths?

The Intersecting Chord Theorem states that if two chords of a circle intersect at a point inside the circle, the products of the lengths of the segments of each chord are equal.

  • For two chords, A B spaceand C D that meet at point P

    • A P colon P D identical to C P colon P B

    • Ratio of longer lengths (of chords) ≡ Ratio of shorter lengths (of chords)

  • This can also be written as A P cross times P B equals C P cross times P D

Diagram illustrating the intersecting chord theorem in a circle. Chords AB and CD intersect at P, forming segments with lengths a, b, c, d, where ab = cd.

Intersecting chord theorem revision resources to ace your exams

You can find out more about the Intersecting Chord Theorem and how it can be used, by reading our revision notes. To test your knowledge, try our exam questions in the circle theorems section.

For quick-fire IGCSE maths revision, use our collection of interactive flashcards for IGCSE maths. We also have past papers for your exam practice.

Explore our IGCSE maths revision resources

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Amber

Reviewer: Amber

Expertise: Maths

Amber gained a first class degree in Mathematics & Meteorology from the University of Reading before training to become a teacher. She is passionate about teaching, having spent 8 years teaching GCSE and A Level Mathematics both in the UK and internationally. Amber loves creating bright and informative resources to help students reach their potential.

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