Geometry


This is an interactive PDF.

Click on the table of contents and it will take you straight to the relevant page.


For a brief overview, click on the arrows below.


Features

Features, sometimes called attributes, are visual characteristics of a shape or object that can be seen.

Properties

Shapes and objects have distinguishable characteristics and are named because of their properties.

The properties of two-dimensional (2D) shapes typically include relationships among the number, length and relative position of sides, as well as the number and angle of corners, lines of symmetry, convexity and concavity.

The properties of three-dimensional (3D) objects typically include the shape and relative position of faces, surfaces, edges and vertices (corners).

Classes (i.e. categories) of shapes are defined by their properties, which are relationships among features of similar shapes.

Properties are relationships connecting characteristics of shapes or objects.

Some properties are defining; that is, they describe what a shape must have to belong to a class.

Classification

Classification involves establishing criteria to group shapes by their common properties. 

Classification is about working with relationships among properties, where individual shapes are examples of the classes and are hierarchical.

Orientation

Orientation is the position of a shape on a plane or an object in space, in particular the direction that the features of the shape or object are facing.

The orientation of a shape remains unchanged as it is translated (i.e. shifted) or enlarged, but changes when a shape is reflected or rotated through an angle not equal to 360°.

Transformation

Transformation is the change in the size, shape or position of a shape or object.

Isometric transformations include translations, rotations and reflections. Note: these do not change the size or proportions of a shape or object.

Non-isometric transformations include enlargements and reductions (dilations).

A dilation is a change to the size of a shape about a point. The lengths of the sides and/or the angles are changed.

Point of view

Objects appear differently depending upon the position from which they are viewed.

Symmetry

A shape has symmetry if it maps onto itself by a transformation, particularly through reflection and/or rotation.

In reflective symmetry, the locations of the mirror are called lines of symmetry.

In rotational symmetry, the point is known as the centre of rotation and the angle of rotation is the measure of turn that maps the shape onto itself.

This is an interactive PDF.

Click on the table of contents and it will take you straight to the relevant page.


For a brief overview, click on the arrow below.

Important concept knowledge list 

For descriptions and examples on the list below, please go to pages 38-40 on the above link.

This is an interactive PDF.

Click on the table of contents and it will take you straight to the relevant page.


For a brief overview, click on the arrows below.


Position

The position of an object on a plane or in space can be specified and described relative to a reference point.

Direction

The direction (i.e. movement) of an object can be described relative to its starting position and surrounding landmarks.

Orientation

The orientation of an object can be described in relation to a reference direction.

Usually the reference direction is a compass point or bearing, or axes on a Cartesian plane.

This is an interactive PDF.

Click on the table of contents and it will take you straight to the relevant page.


For a brief overview, click on the arrows below.


Visual representations

The location of objects on a plane and/or in space can be visually represented; each representation has particular purposes and ways in which they are read and interpreted.

Visual representations include diagrams, plans, grids, maps, directories and networks.

Coordinate systems

A coordinate system is a system used to locate the position or direction of an object on a plane or in space relative to the distance from an origin.

An alpha-numeric grid reference defines a region on a map.

An ordered pair reference defines a point, rather than a region, on a map or Cartesian plane.

Compass points

Cardinal direction

A cardinal direction is a bearing described by north, south, east and west, and is commonly denoted by the direction’s initial.


• north (N) – 0° or 360°

• east (E) – 90°

• south (S) – 180°

• west (W) – 270°.


Inter-cardinal points can also be used:

• north-east (NE) – 45°

• south-east (SE) – 135°

• south-west (SW) – 225°

• north-west (NW) – 315°.


• north-north-east (NNE) – 22.5°

• east-north-east (ENE) – 67.5°

• east-south-east (ESE) – 112.5°

• south-south-east (SSE) – 157.5°

• south-south-west (SSW) – 202.5°

• west-south-west (WSW) – 247.5°

• west-north-west (WNW) – 292.5°

• north-north-west (NNW) – 337.5°.

Bearings

A bearing is the angle between north and another landmark as taken from a fixed point. 

The angle is measured in a clockwise direction.

BOLTSS

BOLTSS (i.e. border, orientations, legend, title, scale and source) is standard information to include on a map:

This is an interactive PDF. 

Click on the table of contents and it will take you straight to the relevant page.

The overarching key ideas have a broad application and are fundamental to enabling students to connect concepts across all areas of mathematics.

Consequently, they need to be considered by educators when developing each unit of work.