CODEWITHSUNDEEP
javaeclipsemethodspolygonarea
seba1685
seba1685

Reputation: 97

Java code - area of a polygon

I have some code with no compile errors, but after I enter the second number while its running it crashes on me :(

Heres what I have:

import java.util.Scanner;
public class Assignment536 {

public static void main(String[] args) {
    Scanner input = new Scanner(System.in);

    System.out.println("Enter the number of sides: ");
    int numberOfSides = input.nextInt();
    System.out.println("Enter the side: ");
    double side = input.nextInt();

    System.out.println("The area of the polygon is: " +area(numberOfSides, side));

    input.close();

}

public static double area(int n, double side) {
    double answer = (n*(side*side))*(4*(Math.tan((Math.PI*n))));
    return answer;
}

}

Any help would be greatly appreciated! Thank you, Sebastian

Upvotes: 0

Views: 4127

Answers (3)

Jamuhuri
Jamuhuri

Reputation: 19

The last part of your formula is wrong. It should be (Math.pi/n) . 

import java.util.Scanner;

public class CalcAreaPolygon {

    public static void main(String[] args){

        Scanner scanner = new Scanner(System.in);

        double area; 
        final double PI;   /method in the formula
        double side;  
        int n;

        PI = Math.PI;

        System.out.println("Enter the number of sides: ");
        n = scanner.nextInt();

        scanner.nextLine();

        System.out.println("Enter the side: ");
        side = scanner.nextDouble();

        area = (n * (side * side)) / (4 * (Math.tan(PI/n)));

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

    }

}

Upvotes: 1

jjlema
jjlema

Reputation: 850

You should change:

final double side = input.nextInt();

for 

final double side = input.nextDouble();

if you want to read a double.

Upvotes: 1

MadProgrammer
MadProgrammer

Reputation: 347204

Add input.nextLine() between the numberOfSlices and side request...

System.out.println("Enter the number of sides: ");
int numberOfSides = input.nextInt();
input.nextLine();
System.out.println("Enter the side: ");
double side = input.nextInt();

After requesting numberOfSlices there is still a carriage return/line feed in the input buffer, when you try and request the side value Scanner fails because it can't convert the the carriage return/line feed to a double type.

Upvotes: 3

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