Each number has that many angles.

I saw a version of this recently with an ugly 9 and other problems, so I thought I'd redo it. Here's the code, maybe someone can improve this more. The seven needs work.

Row[{
Graphics[{AbsoluteThickness[4],Circle[{0,0},{Sqrt[3],7/2}]}],
Graphics[{AbsoluteThickness[4],Line[{{-Sqrt[3],3},{0,4},{0,-3}}]}],
Graphics[{AbsoluteThickness[4],Line[{{-Sqrt[3],4},{Sqrt[3],4},{-Sqrt[3],-3},{Sqrt[3],-3}}]}],
Graphics[{AbsoluteThickness[4],Line[{{-Sqrt[3],4},{Sqrt[3],4},{0,1},{Sqrt[3],-3},{-Sqrt[3],-3}}]}],
Graphics[{AbsoluteThickness[4],Line[{{Sqrt[3],-3},{Sqrt[3],4},{-Sqrt[3],0},{Sqrt[3],0}}]}],
Graphics[{AbsoluteThickness[4],Line[{{Sqrt[3],4},{-Sqrt[3],4},{-Sqrt[3],1},{Sqrt[3],1},{Sqrt[3],-3},{-Sqrt[3],-3},{-Sqrt[3],-2}}]}],
Graphics[{AbsoluteThickness[4],Line[{{Sqrt[3],4},{-Sqrt[3],4},{-Sqrt[3],-3},{Sqrt[3],-3},{Sqrt[3],1},{-Sqrt[3],1}}]}],
Graphics[{AbsoluteThickness[4],Line[{{-Sqrt[3],4},{Sqrt[3],4},{-1,-3}}],Line[{{-Sqrt[3],-3},{0,-3}}],Line[{{0,1},{1,1}}]}],
Graphics[{AbsoluteThickness[4],Line[{{Sqrt[3],1},{Sqrt[3],4},{-Sqrt[3],4},{-Sqrt[3],-3},{Sqrt[3],-3},{Sqrt[3],1},{Sqrt[3],1}}]}],
Graphics[{AbsoluteThickness[4],Line[{{Sqrt[3],1},{0,0},{-Sqrt[3],1},{-Sqrt[3],3},{0,4},{Sqrt[3],3},{Sqrt[3],1},{Sqrt[3],-2},{0,-3},{-Sqrt[3],-2}}]}]},Spacer[5]]