P is a fixed point and a point Q moves such that the distance PQ is constant. What is the locus of the path traced out by the point Q?

Draw and describe the locus of vertices of all isosceles triangles having a common base.

AB is a fixed line. State the locus of point P so that ∠APB = 90°.

Draw and describe the locus of points at a distance 2.5 cm from the fixed line.