The centre and the radius Animation Play

The centre and the radius of a circle Student activity Play

The circle as a locus Animation Play

The circumcentre of a triangle Student activity Play

The circumcentre of a triangle Whiteboard exercise Play

The coordinates of the marked points Whiteboard exercise Play

The coordinates of the vertex of a parabola Animation Play

The correlation coefficient Student activity Play

The correlation coefficient Animation Play

The diameter of the tree Animation Play

The distribution of the rational numbers over the number line Animation Play

The equation describing the line Whiteboard exercise Play

The equation of a horizontal line Animation Play

The equation of a line going through two points Student activity Play

The equation of a line going through two points Whiteboard exercise Play

The equation of a tangent to a circle Whiteboard exercise Play

The equation of a tangent to a circle Student activity Play

The equation of a vertical line Animation Play

The equation of the circle with centre at an arbitrary point Whiteboard exercise Play

The equation of the line Whiteboard exercise Play

The equation of the tangent to a curve Whiteboard exercise Play

The family of lines Student activity Play

The family of lines Whiteboard exercise Play

The family of lines y = 2x + c Animation Play

The figure and its symmetry Whiteboard exercise Play