Match the sentences with the correct words.
(1) A(n) - - is a set of points whose location satisfies a particular description.
(2) A(n) - - is the locus of points in a plane that are equidistant from one point, called the center.
(3) Points that do not lie on the same straight line with other points are - - .
(4) The - - is a segment that extends from the vertex of a cone to the center of the base.
