A conchoid, through the Latin shell (in reference to the shells of mollusks) is a flat curve obtained from a fixed point O (pole), a base curve and a distance k. For each straight line that passes through O that intersects the given curve at a point P, the points N and Q of the straight line located at a distance k from P are obtained. The conchoid is the geometríc locus of the points N and Q when the given curve is crossed by P.
