#5856 area of polygon in C#

code/computational_geometry/src/area_of_polygon/area_of_polygon.cs

@@ -0,0 +1,38 @@
+using System; 
+namespace Cosmos
+{
+	public static class AreaOfPolygon
+	{
+		public static double createShape(){
+            Console.WriteLine("Enter number of sides of the polygon: "); 
+            int n = int.Parse(Console.ReadLine()); 
+            int [] x = new int[n]; 
+            int [] y = new int[n]; 
+            for(int i =0; i < n; i++){
+                Console.WriteLine("Enter x coordinate: "); 
+                x[i] = int.Parse(Console.ReadLine()); 
+                Console.WriteLine("Enter y coordinate: "); 
+                y[i] = int.Parse(Console.ReadLine()); 
+            }
+			return calculateArea(x, y); 
+		}
+
+        public static double calculateArea(int[] xCoords, int[] yCoords){
+            int length = xCoords.Length; 
+            int b; 
+            double area = 0; 
+            for (int i = 0; i < length; i ++){
+                b = (i + 1) % length; 
+                area += xCoords[i] * yCoords[b] - xCoords[b] * yCoords[i]; 
+            }
+            area = Math.Abs(area) / 2.0; 
+            return area; 
+        }
+
+        public static void Main(string[] args)
+    {
+        double area = createShape();
+        Console.WriteLine($"The area of the polygon is: {area}");
+    }
+	}
+}