# 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 (two-dimensional) object such as a triangle or circle.

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

Configuration – the particular arrangement or pattern of a group of related things.

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.