Pythagorean/SOHCAHTOA menu

package javaapplication356;
import java.util.*;
import java.lang.Math;
/**
 *
 * @author Student
 */
public class JavaApplication356 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
       Scanner scan= new Scanner (System.in);
       System.out.println(" ");
       System.out.println("Menu");
       System.out.println("[1] C^2=a^2 + b^2");
       System.out.println("[2] SOH");
       System.out.println("[3] CAH");
       System.out.println("[4] TOA");
       System.out.print("Enter choice: ");
       int a=scan.nextInt();
       System.out.println("     ");
       if (a==1){
           System.out.println("[1] C^2= a^2 + b^2");
           System.out.print("Enter a: ");
           double b = scan.nextDouble();
           System.out.print("Enter b: ");
           double c = scan.nextDouble();
           double d = (Math.pow(b,2)+ Math.pow(c, 2));
           System.out.println(Math.sqrt(d));
           }
       else if (a==2){
           System.out.println("SOH");
           System.out.print("Enter Opposite: ");
           double e=scan.nextDouble();
           System.out.print("Enter Hypotenuse: ");
           double f=scan.nextDouble();
           System.out.println(e/f);
           }
       else if (a==3){
           System.out.println("CAH");
           System.out.print("Enter Adjacent: ");
           double g=scan.nextDouble();
           System.out.print("Enter Hypotenuse: ");
           double h=scan.nextDouble();
           System.out.println(g/h);
           }
       else if (a==4){
           System.out.println("TOA");
           System.out.print("Enter Opposite: ");
           double i=scan.nextDouble();
           System.out.print("Enter Adjacent: ");
           double j=scan.nextDouble();
           System.out.println(i/j);
           }
       else {
           System.out.println("Try again");}
       }

}