Hypotenuse - GCSE Maths Definition
Reviewed by: Mark Curtis
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What is the hypotenuse?
In GCSE maths, the hypotenuse is the name given to the longest side of a right-angled triangle. It is the side opposite the right angle.
It is important to know which length is the hypotenuse when using Pythagoras’ theorem (it is the length ‘c’ in the formula a2 + b2 = c2).

Knowing which length is the hypotenuse is also necessary when using trigonometry (sin, cos and tan). The names of the two shorter sides are the ‘opposite’ side and the ‘adjacent’ side, depending on where the angle is.

Hypotenuse revision resources to ace your exams
The hypotenuse is covered in our revision notes on Pythagoras’ theorem and trigonometry from GCSE Maths. You can also have a go at our related exam questions and flashcards to test your understanding. Don’t forget to check out the past papers for more general exam revision.
Need help reaching your target grade? Explore our notes, questions by topic and worked solutions, tailor-made for GCSE Maths.
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