Parametric Drawing

PPRT[n_,col_,s_]:=Module[{a,b,c,u},
u=Pi/n; a=RandomInteger[{5,12}];
b=RandomInteger[{13,24}];c=2*RandomInteger[{3,6}];
PF1[i_,t_]:=Cos[u*t+2i*Pi/c]+Cos[a*u*t+2i*Pi/c]+Cos[b*u*t+2i*Pi/c];
PF2[i_,t_]:=Sin[u*t+2i*Pi/c]-Sin[a*u*t+2i*Pi/c]+Sin[b*u*t+2i*Pi/c];
Show[Table[ParametricPlot[{PF1[i,t],PF2[i,t]},{t,0,12Pi},
PlotStyle->{ColorData[col][i/c],Thickness[.001]}],{i,c}],
PlotRange->All,Background->RGBColor["silver"],PlotPoints->200,
Axes->False,PlotLabel->{"a"->a,"b"->b,"c"->c},ImageSize->s]]
PPRT[11,"BrightBands",600]