The area of a triangle Animation Play

The circle and the equilateral triangle Student activity Play

The exterior angle of a regular polygon Student activity Play

The exterior angle of a regular polygon – proof (1) Animation Play

The exterior angle of a regular polygon – proof (2) Animation Play

The factor theorem – proof Animation Play

The Integer Root Theorem – proof Animation Play

The interior angle of a regular polygon Student activity Play

The interior angle of a regular polygon – proof (1) Animation Play

The interior angle of a regular polygon – proof (2) Animation Play

The perimeter of the triangle and the diameter of the big circle Animation Play

The Rational Root Theorem – proof Animation Play

The sum of a positive number and its reciprocal Animation Play

The sum of the angles in a polygon Student activity Play

The sum of the exterior angles of a convex polygon Student activity Play

The sum of the interior angles of a quadrilateral – proof Animation Play

Theorems and their assumptions in algebra Student activity Play

Theorems and their assumptions in algebra Whiteboard exercise Play

Theorems and their assumptions in geometry Student activity Play

Understanding the theorem Class activity Play

Understanding the theorem Whiteboard presentation Play

When is a theorem true? The proof Student activity Play

Wrong steps in reasoning Student activity Play