The normal Whiteboard presentation Play

The notion of a half-plane Whiteboard exercise Play

The notion of a half-plane Student activity Play

The number line Whiteboard exercise Play

The number of car accidents Animation Play

The origin of spectral lines Animation Play

The perpendicular bisector Student activity Play

The perpendicular bisector of a line segment Animation Play

The perpendicular bisector of a line segment – a reminder Student activity Play

The points on a straight line Animation Play

The price of a ball-pen Whiteboard exercise Play

The price of petrol Whiteboard exercise Play

The properties of stars Whiteboard exercise Play

The properties of stars Student activity Play

The red line Whiteboard exercise Play

The scalar product (1) Whiteboard presentation Play

The second tangent theorem Animation Play

The second tangent theorem – equality in length Student activity Play

The second tangent theorem – equality in length Whiteboard exercise Play

The shortest route to a line Whiteboard exercise Play

The shortest route to a line Student activity Play

The solution set of a system of inequalities Student activity Play

The solution set of inequality Whiteboard exercise Play

The solution set of the linear equations Whiteboard exercise Play

The spectral lines in the atomic spectrum of hydrogen Animation Play