#458 Distance formula, gradient of a line and coordinates of a midpoint
#459 Area of a triangle, size of an angle and coordinates of an x intercept
#460 Determining the gradient given a point and a midpoint
#527 Finding a point and calculating distance
#528 Working with circle functions
#531 Determine the coordinates of the centre of a circle
#549 Mastering analytical geometry
#550 Working with a circle on a Cartesian plane
#479 The equation of a line and finding coordinates