lsp_wrong.cs

namespace SolidRules.LSP
{
    public class Rectangle
    {
        protected double Width { get; }
        private double Height { get; }

        public Rectangle(double width, double height)
        {
            Width = width;
            Height = height;
        }

        public virtual double GetSquare() => Width * Height;
    }

    // violates LSP
    public class Square : Rectangle
    {
        public override double GetSquare() => Width * Width;

        public Square(double width, double height) : base(width, height) { }
    }
}