mathematica如何将以下分段参数方程绘制出来？

a1 = PolarPlot[{Sqrt[((38.5 -
3.5 Cos[3 \[Delta]]) Sin[\[Delta]])^2 + ((38.5 -
3.5 Cos[3 \[Delta]]) Cos[\[Delta]])^2]}, {\[Delta],
0 \[Degree], 60 \[Degree]}]
a2 = PolarPlot[{Sqrt[(42 Sin[\[Delta]])^2 + (42 Cos[\[Delta]])^2]}, {\
\[Delta], 60 \[Degree], 65 \[Degree]}]
a3 = PolarPlot[{Sqrt[((38.5 +
3.5 Cos[3 (\[Delta] -
65 \[Degree])]) Sin[\[Delta]])^2 + ((38.5 +
3.5 Cos[3 (\[Delta] -
65 \[Degree])]) Cos[\[Delta]])^2]}, {\[Delta],
65 \[Degree], 125 \[Degree]}]
a4 = PolarPlot[{Sqrt[(35 Sin[\[Delta]])^2 + (35 Cos[\[Delta]])^2]}, {\
\[Delta], 125 \[Degree], 360 \[Degree]}]
Show[a1, a2, a3, a4]