GeometryCalculator

using System;

namespace _11.GeometryCalculator
{
    class StartUp
    {
        static void Main()
        {
            // Choosing the figure
            string typeOfFigure = Console.ReadLine();
            if (typeOfFigure == "triangle")
            {
                double side = double.Parse(Console.ReadLine());
                double height = double.Parse(Console.ReadLine());
                Console.WriteLine($"{GetTriangleArea(side,height):f2}");
            }
            else if (typeOfFigure == "rectangle")
            {
                double width = double.Parse(Console.ReadLine());
                double height = double.Parse(Console.ReadLine());
                Console.WriteLine($"{GetRectangleArea(width,height):f2}");
            }
            else if (typeOfFigure == "square")
            {
                double side = double.Parse(Console.ReadLine());
                Console.WriteLine($"{GetSquareArea(side):f2}");
            }
            else if (typeOfFigure == "circle")
            {
                double radius = double.Parse(Console.ReadLine());
                Console.WriteLine($"{GetCircleArea(radius):f2}");
            }
        }
        // Calculating the area of the triangle.
        public static double GetTriangleArea(double side, double height)
        {
            double triangleArea = side * height / 2;
            return triangleArea;
        }
        // Calculating the area of the rectangle.
        public static double GetRectangleArea(double width,double height)
        {
            double rectangleArea = width * height;
            return rectangleArea;
        }
        // Calculating the area of the square.
        public static double GetSquareArea(double side)
        {
            double areaSquare = side * side;
            return areaSquare;
        }
        // Calculating the area of the circle.
        public static double GetCircleArea(double radius)
        {
            double circleArea = Math.PI * radius * radius;
            return circleArea;
        }
    }
}