**Glossary of key maths terms**

**Algorithm ** – a step-by-step set of instructions to perform a particular task

**Angle **– an angle is the figure formed by two lines sharing a common end, which is called the vertex of the angle (like the corner of a page).

**Area** – the amount of space inside the boundary of a flat (2-dimensional) object such as a triangle or circle.

**Buoyancy – **an upward force exerted by a fluid that opposes the weight of an immersed object.

**Drag – **a force which slows objects due to air resistance.

**Estimation – **an approximate calculation of something.

**Geometry** – Geometry is the study of shapes and sizes, angles and lines. It is one of the oldest forms of mathematics. Symmetry is one part of geometry.

**Gravity –** the force that pulls objects towards the ground.

**Horizontal **– an object is in a horizontal position if it is lined up with a flat surface. For example, a tabletop or a benchtop is horizontal.

**Lift – **the upwards force caused by pushing air downwards.

**Line Symmetry** – an object has line symmetry (also known as Mirror Symmetry) if a line (axis) can be drawn on the object to divide it into two halves in such a way that when the object is folded along that line the two halves correspond or match up.

**Mass – **a measure of how much matter is in an object.

**Perimeter** – the distance around the boundary of a two-dimensional shape.

**Polygon** – A polygon is a 2D shape with at least three straight sides and angles. A polygon is regular when all angles and all sides are equal, otherwise it is an irregular polygon. Examples of polygons are hexagons, octagons and pentagrams.

**Rotational Symmetry** – an object has rotational symmetry when it can rotate around its centre and fit in to itself more than once. For example a rectangle has two orders of rotational symmetry because it looks exactly like the original after half a turn. If a shape only fits into itself once, it has no rotational symmetry.

**Symmetry** – an object has symmetry if it can be rotated, shifted, or reflected and still end up looking like the original shape. The two main types of Symmetry are Line and Rotational.

**Thrust** **–** a generated force which moves an object forward.

**Vertical** – an object is in a vertical position if it runs up or down. For example, a table leg or chair leg is usually in a vertical position.

## Want to learn more maths words? Try these links

The Victorian Curriculum has a **Mathematics Glossary **(downloads a Word doc).

Try looking at this** Maths A to Z** list.