using System;

​

public class Program

{

    public static void Main()

    {

        decimal vWidth, vHeight, vBase, vLength;

        double vRadius, PI = Math.PI;

        Console.WriteLine(" please enter a width ");

        vWidth = decimal.Parse(Console.ReadLine());

        Console.WriteLine(" please enter a height ");

        vHeight = decimal.Parse(Console.ReadLine());

        vBase = decimal.Parse(Console.ReadLine());

        Console.WriteLine(" please enter a base");

        Console.WriteLine(" please enter a radius");

        vRadius = double.Parse(Console.ReadLine());

        Console.WriteLine(" please enter a length");

        vLength = decimal.Parse(Console.ReadLine());

        Console.WriteLine(" area of Triangle: " + (vBase + vHeight) / 2);

        Console.WriteLine(" area of Square: " + (vWidth + vWidth));

        Console.WriteLine(" area of Rectangle: " + (vWidth + vHeight));

        Console.WriteLine(" area of Trapezium: " + (vBase + vLength) / 2);

        Console.WriteLine(" area of Circle: " + (vRadius * vRadius * PI));

    }

}