Calculator By inheritance.

import java.util.Scanner;
import java.lang.Math;
class Calc
{
static int a,b;
static Scanner sc = new Scanner(System.in);
//////////////////////////////////////////
static void input1()
{
  System.out.println("Enter a no:");
  a = sc.nextInt();
  System.out.println("Enter a no:");
  b = sc.nextInt();
}
static void input2()
{
  System.out.println("Enter a no:");
  a = sc.nextInt();
}
/////////////////////////////////////////
static int add(int a,int b)
{
  return a+b;
}
static int sub(int a,int b)
{
return a-b;
}
static int mul(int a,int b)
  {
  return a*b;
}
static int div(int a,int b)
{
  return a/b;
}
static int sqr(int a)
{
  return a*a;
}
static double sqroot(double a)
{
  return Math.sqrt(a);
}
}
class Calculator extends Calc
{
static double c;
static void input3()
{
  System.out.println("Enter a no:");
c = sc.nextDouble();
}
  static double sine(double d)
{
  return Math.sin(Math.toRadians(d));
}
static double cosine(double d)
{
  return Math.cos(Math.toRadians(d));
}
static double tann(double d)
{
  return Math.tan(Math.toRadians(d));
  }
static double asine(double d)
{
    return Math.asin(d);
}
static double acosine(double d)
{
return Math.acos(d);
}
static double atann(double d)
{
  return Math.atan(d);
}
public static void main(String...args)
  {
  System.out.println("----Menu----");
  System.out.println("1.Add \n2.Sub \n3.Mul \n4.Div \n5.Sqr \n6.Sqr Root \n7.Sin \t\t8.Cos \t\t9.Tan \n10.Asin \t11.Acos \t12.Atan");
    int m = sc.nextInt();
  switch(m)
    {
  case 1:
    input1();
    System.out.println("\n"+a+"+"+b+"="+add(a,b));
    break;
  case 2:
    input1();
    System.out.println("\n"+a+"-"+b+"="+sub(a,b));
    break;
  case 3:
    input1();
    System.out.println("\n"+a+"*"+b+"="+mul(a,b));
    break;
  case 4:
    input1();
    System.out.println("\n"+a+"/"+b+"="+div(a,b));
    break;
  case 5:
      input2();
    System.out.println("\nSquare of "+a+"="+sqr(a));
    break;
  case 6:
    input2();
    System.out.println("\nSquare root of "+a+"="+sqroot(a));
    break;
    case 7:
    input3();
    System.out.println("\nSine("+c+")="+sine(c));
    break;
  case 8:
    input3();
    System.out.println("\nCos("+c+")="+cosine(c));
    break;
  case 9:
    input3();
    System.out.println("\nTan("+c+")="+tann(c));
    break;
  case 10:
    input3();
    System.out.println("\nAsin("+c+")="+asine(c));
    break;
  case 11:
    input3();
    System.out.println("\nACos("+c+")="+acosine(c));
    break;
  case 12:
    input3();
    System.out.println("\nAtan("+c+")="+atann(c));
    break;
    default:
    System.out.println("Wrong Entry");
}
}
}