Bisect: GCSE Maths Definition

What does bisect mean?

A ‘bisector’ is something that bisects another object. So a line that bisects a line segment at a right angle is known as a ‘perpendicular bisector’, or a line that bisects an angle is known as an ‘angle bisector’.

‘Bisect’ is a mathematical term that means ‘cut in half’. This occurs in GCSE Maths in the ‘constructions’ topic. You need to know how to use a pair of compasses and a straight edge to bisect an angle, or to perpendicularly bisect a line segment (i.e. cut it in half at a right angle).

‘Bisect’ and ‘bisector’ can also occur in other GCSE Maths topics. For example, when learning the properties of two-dimensional shapes, you should learn that the diagonals of a rectangle bisect each other. This means if you draw the two lines from corner to corner across the middle of a rectangle, they will cut each other in half.

GCSE Maths Revision Resources to Ace Your Exams

To see how to bisect line segments or angles using a pair of compasses and a straight edge, read our revision notes on Constructions & Loci. 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.

Explore GCSE Maths revision resources