public static bool IsPerpendicular(Line2D x, Line2D y) => x.A * y.A + x.B * y.B == 0;
public static bool IsParallel(Line2D a, Line2D b) => a.A / b.A == a.B / b.B;
/// <summary>
/// Конструктор копирования
/// </summary>
/// <param name="l"></param>
public Line2D(Line2D l)
{
A = l.A; B = l.B; C = l.C;
}
