/// <summary>
/// 取得中垂線
/// </summary>
/// <param name="e">線</param>
/// <returns>中垂線</returns>
public static Edge GetBisector(this Edge e)
{
PointF mid = MathEx.GetMidPointF(e.A, e.B);
return(new Edge(mid.Add(GetNormalVector(e.A, e.B).Multi(600)), mid.Add(GetNormalVector(e.B, e.A).Multi(600)), e.A, e.B));
}