Properties and constructions
Groups
Lines, angles and labelling
The words, marks and conventions a diagram is written in.
Angles on parallel lines
The three angle pairs a transversal makes with parallel lines.
Angles in triangles and polygons
The angle sum a triangle forces on every polygon.
Quadrilaterals and symmetry
What defines each special quadrilateral.
Congruent triangles
The four criteria that force two triangles to be identical.
Similar shapes
When two shapes count as similar, the reasoning that proves it.
Constructions and loci
The ruler-and-compass constructions, the loci each one draws.
Transformations
The four transformations on axes, described precisely.
Circles and their theorems
The names for a circle’s parts.
Solids, plans and coordinates
Flat representations of solid shapes — counts of faces and edges, nets.