The first tangent theorem – perpendicularity Student activity Play

The investment – a more difficult problem Student activity Play

The isosceles triangle Whiteboard exercise Play

The perimeter of the rectangle Whiteboard exercise Play

The problem of de Méré Animation Play

The problem of drug addiction Student activity Play

The problem of drug addiction Whiteboard exercise Play

The Professor's number Animation Play

The quadratic equations Animation Play

The quadratic formula Whiteboard presentation Play

The quadratic formula Class activity Play

The quickest method Animation Play

The scatter plot for bird density Student activity Play

The solution of the equation Student activity Play

The solution of the equation Whiteboard exercise Play

The Superb Sandwich Company Animation Play

The tangent theorem – solving problems Whiteboard exercise Play

The unknown on both sides of the equation Student activity Play

The unknown on both sides of the equation Whiteboard exercise Play

The unknowns Whiteboard exercise Play

Think of a number Whiteboard exercise Play

Think of a number Student activity Play

Time – a more difficult problem Student activity Play

Time – a more difficult problem Whiteboard exercise Play

Transposing the formula Student activity Play