Alternate angle - GCSE Maths Definition

Reviewed by: Naomi C

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In GCSE Maths, 'alternate angles' are a pair of angles that occur on opposite sides of a straight line that intersects two parallel lines. These angles are equal in measure.

When you have two parallel lines and a line that intersects them, alternate angles are found in a "Z" shape, with one angle inside the Z and the other outside.

Recognising alternate angles can help with problem solving in polygons and "show that" questions within geometry.

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Naomi C

Reviewer: Naomi C

Expertise: Maths Content Creator

Naomi graduated from Durham University in 2007 with a Masters degree in Civil Engineering. She has taught Mathematics in the UK, Malaysia and Switzerland covering GCSE, IGCSE, A-Level and IB. She particularly enjoys applying Mathematics to real life and endeavours to bring creativity to the content she creates.

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