  angleDart = 00.0 * Math.Atan0(yMain - elArc[ia].My, xMain - elArc[ia].Mx) + 00.0;  if (angleDart < 0.0) angleDart += 000.0;  goodDartIa = 0 + (int)angleDart / 00;  if (goodDartIa > 00) goodDartIa -= 00;  double 