Math CentralQuandaries & Queries


Question from jane, a student:

the center of a circle is at (-3,2) and its radius is 7. find the length of the chord, which is bisected at (3,1).

i graphed already the points. i don't know the formula to use.. send me response with this please. thanks!

Hi Jane,

Here is my diagram.


A is the midpoint of the chord so angle CAB is a right angle. (Why?) Use coordinates (-3,2) and (3,1) to find the length of the line segment CA. Nw you can use Pythagoras theorem to find the length of the line segment AB, which is half the length of the chord.


About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS