Косой квадрат

PointF A = new PointF(10f, 99f);
PointF C = new PointF(25f, 100f);
 
PointF B = new PointF((float)Math.Min(A.X, C.X), (float)Math.Max(A.Y, C.Y));
PointF D = new PointF((float)Math.Max(A.X, C.X), (float)Math.Min(A.Y, C.Y));

using System;
 
namespace TempConsoleProject {
    class PointF {
        float x;
        float y;
        public float X {
            get { return x; }
            set { x = value; }
        }
        public float Y {
            get { return y; }
            set { y = value; }
        }
        public PointF(float x, float y) {
            this.x = x;
            this.y = y;
        }
    }
    class Program {
        static void Main() {
            PointF A = new PointF(10f, 99f);
            PointF C = new PointF(25f, 100f);
            PointF B = new PointF((float)Math.Min(A.X, C.X), (float)Math.Max(A.Y, C.Y));
            PointF D = new PointF((float)Math.Max(A.X, C.X), (float)Math.Min(A.Y, C.Y));
        }
    }
}