Learning Resources

Focus D: Chord Properties in a Coordinate System

Test yourself (solution)

As always, first sketch the points on a coordinate system.

1. Use either point to find the radius:

2. The distance from a point to a line is perpendicular distance. But from the centre perpendicular to the chord, meets it at its mid-point. So  first find the mid-point of GF.

   Now find length of EM (where M is the midpoint of GF).

Thus the radius is 10 and the distance from the centre to the chord FG is .