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>
Yes. Their sum can be equal to 1 because if they have the same denominator they will add easier like 3/4 and 1/4 or 1/2 and 1/2. All of them have the same denominator and still equal 1