public IList <SquareEquation> GetAllSquareEquations()
 {
     using (var ctx = new SquareEquationContext())
     {
         return(ctx.SquareEquations.ToList());
     }
 }
        public void AddSquareEquation(SquareEquation equation)
        {
            using (var ctx = new SquareEquationContext())
            {
                ctx.SquareEquations.Add(equation);

                ctx.SaveChanges();
            }
        }