CODEWITHSUNDEEP
javamath
53300
53300

Reputation: 23

Math.atan isn't working

very beginner programmer here (Started 2 weeks ago), I'm currently having problems with Math.atan. I currently use the Eclipse IDE and I have been trying to find out how to do tan^-1 for a triangle but it currently isn't working. I inputted 10 and 5 into the console but it comes out with 0.4636476090008061 when the actual answer is something like 63.43494882. I tried converting side1Two and side2Two into degrees, but it didn't work.

    import java.util.Scanner;
    public class triangleParts {

        public static void main(String[] args) {
    /*
     *        |\
     *        |A\
     *        |  \
     * Side 1 |   \ 
     *        |_   \
     *        |_|__B\
     *         Side 2
     */
        Scanner side1 = new Scanner(System.in);
    System.out.println("Input side 1 here:");
        double side1Two = side1.nextDouble(); 

        Scanner side2 = new Scanner (System.in);
    System.out.println("Input side 2 here:");
        double side2Two = side2.nextDouble();

    //Hypotenuse//
    double hypotenuse = (Math.sqrt((side1Two * side1Two) + (side2Two * side2Two)));
        System.out.println("Hypotenuse");
        System.out.println(hypotenuse);
    //Angle A//
    double angleA = (Math.atan(side2Two/side1Two));
        System.out.println("Angle A");
        System.out.println(angleA);
    //Angle B//
    double angleB = (Math.atan(side1Two/side2Two));
        System.out.println("Angle B");
        System.out.println(angleB);



        }

    }

Upvotes: 1

Views: 570

Answers (3)

Sash Sinha
Sash Sinha

Reputation: 22275

Here is your code fixed to use only one scanner, and converting to degrees since the output of Math.atan is in radians:

import java.util.Scanner;

class Main {
  public static void main(String[] args) {
    /*
     *        |\
     *        |A\
     *        |  \
     * Side 1 |   \ 
     *        |_   \
     *        |_|__B\
     *         Side 2
     */
    System.out.println("53000's Simple Java Trigonometry Program");
    System.out.println("========================================");

    Scanner sc = new Scanner(System.in); //Declare Scanner

    System.out.print("Input the length of side 1 here:");
    double side1 = sc.nextDouble();

    System.out.print("Input the length of side 2 here:");
    double side2 = sc.nextDouble();

    //Hypotenuse
    double hypotenuse = (Math.sqrt((side1 * side1) + (side2 * side2)));
    System.out.println("The length of the Hypotenuse is: " + hypotenuse);

    //Angle A
    double angleA = Math.toDegrees((Math.atan(side2/side1)));
    System.out.println("The size of Angle A is: " + angleA);

    //Angle B
    double angleB = Math.toDegrees((Math.atan(side1/side2)));
    System.out.println("The size of Angle B is: " + angleB);
  }
}

Try it here!

Upvotes: 0

azro
azro

Reputation: 54148

//Angle A//
double angleA = Math.toDegrees((Math.atan(side2Two/side1Two)));
System.out.println("Angle A");
System.out.println(angleA);
//Angle B//
double angleB = Math.toDegrees((Math.atan(side1Two/side2Two)));
System.out.println("Angle B");
System.out.println(angleB);

This, is working ;)

Upvotes: 0

Abdulgood89
Abdulgood89

Reputation: 389

As Hovercraft Full Of Eels mentioned, the method returns a radian value, not a degree value. You can use the following built-in method to make it into degrees:

 double getDegrees = Math.toDegrees((Math.atan(side2Two/side1Two)))

Upvotes: 1

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