Write a program that prompts the user to enter the length from the center of a pentagon to a vertex and computes the area of the pentagon, where r is the length from the center of a pentagon to a vertex.
(Hint: Length of the side =2*length from the center to a vertex * sine(PI/5)
Area = (5 * Math.pow(side, 2)) / (4 * Math.tan(Math.PI /5));
For rounding to two decimal points uses String.format(“%.02f”,variablename))
INPUT
6.4 // Length from the center of a pentagon to a vertex
OUTPUT
97.39 // Area of pentagonimport java.io.*;
import java.util.*;
import java.lang.Math;
public class temp {
public static void main(String[] args) {
double length , side , area;
Scanner scan = new Scanner(System.in);
System.out.println("Enter the Length from the center of a pentagon to a vertex: ");
length = scan.nextDouble();
side = 2 * length * Math.sin(Math.PI/5);
area = (5 * Math.pow(side,2)) / (4 * Math.tan(Math.PI/5));
System.out.println("Area of the pentagon: "+String.format("%.02f",area));
}
}
INPUT_1:
Enter the Length from the center of a pentagon to a vertex:
6.4
OUTPUT:
Area of the pentagon: 97.39
INPUT_2:
Enter the Length from the center of a pentagon to a vertex:
5.9
OUTPUT:
Area of the pentagon: 82.77
INPUT_3:
Enter the Length from the center of a pentagon to a vertex:
7
OUTPUT:
Area of the pentagon: 116.50
INPUT_4:
Enter the Length from the center of a pentagon to a vertex:
5.2
OUTPUT:
Area of the pentagon: 64.29
INPUT_5:
Enter the Length from the center of a pentagon to a vertex:
10
OUTPUT:
Area of the pentagon: 237.76
ILLUSTRATION
