## Saturday, 20 August 2016

### Chapter 6 Exercise 36, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

*6.36 (Geometry: area 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 isWrite 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: 6.5 The area of the polygon is 72.69017017488385

import java.util.Scanner;

public class ProgrammingExercise6_38 {

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter the number of sides:");
int n = input.nextInt();

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

System.out.println("The area of the polygon is " + area(n, s));

}

public static double area(int n, double side) {

return n * Math.pow(side, 2) / (4 * Math.tan(Math.PI / n));
}

}