static void Main(string[] args)
{
var quad1 = new Quadrillateral {
Leg1 = 2, Leg2 = 4, Leg3 = 6, Leg4 = 8
};
quad1.GetPerimeter();
var rect1 = new Rectangle(5, 7)
{
};
rect1.GetPerimeter();
rect1.GetArea();
var sq1 = new Square(7)
{
};
sq1.GetPerimeter();
sq1.GetArea();
}