Class to go out onto tennis court. One pupil to be fixed point others to stand 3 metres away from that pupil,what shape do they stand in? Next have four pupils standing in a line , others must stand 2 metres from that line, what shape do they stand in? Use the corner of the court pupils to stand equidistant from the lines that make that corner, what shape do they make? Again take the corner, pupils must stand 5metres from that corner inside the court and then try outside the court, What shape? Two pupils in fixed positions the rest must stand equidistant from them, What shape? This can be continued with any other loci.