AQA GCSE Mathematics key terms

An algebraic expression written as one expression divided by another, with a denominator that must not equal zero.

A mathematical representation of a real situation, relationship or procedure.

Angles at different intersections on opposite sides of a transversal, either both between the two lines or both outside them. They are equal when those lines are parallel.

The rule that the angle between a tangent and a chord equals the angle subtended by that chord in the opposite segment of the circle.

The angle that measures how far one direction turns from another, measured in degrees (°).

The angle formed by the line segments $BA$ and $BC$, with its vertex at the middle letter $B$.

A line or ray that divides an angle into two equal angles; points on it are equally far from the angle’s sides.

A known angle and the side directly opposite it in a triangle.

An angle formed by joining a point to both endpoints of an arc.

The vertex of a cone or pyramid opposite its base.

A solution estimated from a graph or rounded decimal calculation rather than given exactly.

A value used in place of another value because it is sufficiently close for the purpose.

A part of a circle's circumference between two points.

The amount of surface enclosed by a 2D shape, measured in square units.

The multiplier that changes corresponding areas, including surface areas, from one similar figure to another.

The region between a graph and the horizontal axis over a stated interval. Its units are the vertical-axis units multiplied by the horizontal-axis units.

The angle used as the input of a trigonometric function; in this topic it is measured in degrees.

A sequence in which the difference between consecutive terms is constant.

Arranging values from smallest to largest.

A line that a curve approaches increasingly closely without reaching. For exponential growth and decay graphs, the $x$-axis, $y=0$, is a horizontal asymptote.

The constant rate that represents the overall change between two points on a graph; it is the gradient of the chord joining them.

The bearing for travelling back along the same straight line in the opposite direction.

The amount in an account after its credits and debits have been taken into account.

A chart in which separate, equal-width bars represent categories and each bar's height shows its frequency.

The quantity that is repeatedly multiplied in a power. In $x^5$, the base is $x$.

A systematic effect that makes the collected data unrepresentative of the population.

An algebraic expression consisting of exactly two unlike terms joined by addition or subtraction, such as $x+3$ or $2x-5$.