Maths Terms for 11-13 Yr Olds

The value of the non-zero coordinate of the point where a line on a graph cuts an axis. The y intercept is given the symbol c in straight line graphs of the form y = mx + c.

At a vertex of a polygon, the angle that lies within the polygon.

To have an intersect is to have a common point or points. Examples: Two intersecting lines intersect at a point; two intersecting planes intersect in a line.

Operations that, when they are combined, leave the entity on which they operate unchanged. Examples: addition and subtraction are inverse operations e.g. 5 + 6 - 6 = 5. Multiplication and division are inverse operations e.g. 6 × 10 / 10 = 6.

Some operations, such as reflection in the x-axis, are self-inverse.

A triangle in which two sides have the same length and consequently two angles are equal. This definition includes an equilateral triangle as a special case.

Symbol: kg. The base unit of mass in SI units ('Système International d'Unités' in French, also known as metric). 1kg. = 1000g.

Symbol: km. A unit of length in SI units ('Système International d'Unités' in French, also known as metric). 1km. = 1000m.

A set of adjacent points that has length but no width. A curve. A straight line is completely determined by two of its points, say A and B. The part of the line between any two of its points is a line segment.

In algebra, an adjective describing an expression, equation or relationship of degree one. Example: 2x + 3y = 7 is a linear equation. This linear equation with its two variables, x and y, can be represented as a straight line graph. The relationship between x and y is linear.