Question

A set of points that are equidistant from a fixed point in three-dimensional space is known as .

Answer 1

A sphere is a collection of those points that are at a fixed distance from a fixed point in three dimensions.

Consider the following figure,


Here, $O$ is the fixed point, which is known as the centre of the sphere, while all other points $A,B,C,D,E,F,G$, and $H$ are at equal distance from the point $O$.

The distance of these points from $O$ is known as the radius of the sphere.