(Geometry of a regular polygon) A regular polygon is an n-sided polygon in which all sides are of the same length and all angles have the same degree (i.e., the polygon is both equilateral and equiangular).  The formula for computing the area of a regular polygon is

Write a method that returns the area of a regular polygon using the following header:

public static double area(int n, double side)

Write a main method that prompts the user to enter the number of sides and the side of a regular polygon and displays its area.  Here is a sample run:

Enter the number of sides: 5
Enter the side: 6.4
The area of the polygon is 72.69017017488385

PolygonArea.java

/**
 * Geometry of a regular polygon 
 */

	import java.util.Scanner; // import Scanner object.
public class PolygonArea {

    /** main method */
    public static void main(String[] args) {

    	//	Create Scanner Object.
    	Scanner input = new Scanner(System.in);

    		// Get number of sides.
    		System.out.print("Enter the number of sides: ");
    			int n = input.nextInt();

    		// Get side length.
    		System.out.print("Enter the side: ");
    			double side = input.nextDouble();

    	double area = area(n,side); // Use area method.
    		System.out.print("The area of the polygon is: "+area); // Print area.

    } // End of main method.

    /** Area calculation method */
    public static double area(int n, double side){

    	double result = (n*Math.pow(side,2))/(4*Math.tan(Math.PI/n)); // area calculation formula.
		return result;	// Return area.

    } // End of area method.
} // End of Area class