The given definition of a circle is the set of all points that are the same distance from one given point
One example that contradicts the definition, is the set of all points in a three dimensional plane which are equidistant from, a point, which is the definition of a sphere
Part B
The definition of a circle can be modified to include the location of the points <em>on the same plane</em>, from which we therefore have;
<em>A circle is a set of all points on a plane that are the same distance from one given point</em>
