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?

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.

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