How to covert Decimal

Question

I am trying to set twp decimal places in my result . I used
DecimalFormat and Round , I can get round for one decimal
palce but I need two decimal instead of one.
Since I am new for programming I may be not know to implement
Decimal format or round . I need help.
here is may code.
public class Circle {
public static final double pi = 3.14159;
double x = 5.00;
double y = 3.00;
double r ;
Circle(double x, double y, double r) {
r = 5.0;
x = 20.0;
y = 15.0;
this.x = x;
this.y = y;
this.r = r;
Circle() {
public double circumference() {
return 2 * r * pi;
public double area() {
return pi * r * r;
public void setRadius(double r) {
double Max;
Max = 30;
r = 5;
if ( r > Max) {
r = Max;
public void printAttributes () {
System.out.println(" Circumference is:" + circumference() );
System.out.println(" Area is:"+ area() );
System.out.println(" Radius is :"+ 2*pi / circumference() );
System.out.println(" Coordinates are + x , + y ");
public boolean isInside ( int x, int y) {
double dx;
double dy;
dx = x - this.x;
dy = y - this.y;
double dist ;
dist = Math. sqrt(dx * dx + dy * dy);
return (dist < r);
// if (dist < radius )
// return true;
//else
// return false;
void boundingBox() {
double tlx = x - r;
double tly = y - r;
double brx = x + r;
double bry = y + r;
//Top left Coordinators = tlx + tly;
//Top right Coordinators = brx + bry;
System.out.println( " Top left Coordinators: +tlx , +tly " );
System.out.println( " Top right Coordinators:+brx , +bry" );
void move (int x , int y) {
this. x = x;
this. y = y;
public static void main ( String args [] ) {
/**public static float roundUp (float value){
     int num ;
value=(float)(value*1000+.5);
     num=((int)value);
float d=(float)num;
d=d/1000;
return d;
Circle C = new Circle ();
C. r = 2.0;
C. x = 5.0;
C. y = 3.0;
Circle area = new Circle ();
Circle circumference = new Circle ();
//Circle Coordinators = new Circle (5, 3);
C. circumference ();
C. area ( );
C. printAttributes ();
C. move (-4, 5);
C. boundingBox () ;

Answer 1

I don't really understand your post so I'll just give you an example.
If I had a radius (in double format) and I wanted to return the circumference in double format rounded to 2 decimal digits, I would use this code:
    double radius = 5.00;
    BigDecimal tmp = new BigDecimal(radius * Math.PI * 2); // 2 * PI * R
    tmp = tmp.setScale(2, BigDecimal.ROUND_HALF_EVEN);
    double circum = tmp.doubleValue();
    return circum;And if I wanted the area, I'd use this code:
    double radius = 5.00;
    BigDecimal tmp = new BigDecimal(Math.pow(radius, 2.0) * Math.PI); // 2 * PI * R
    tmp = tmp.setScale(2, BigDecimal.ROUND_HALF_EVEN);
    double area = tmp.doubleValue();
    return area;Just apply that to your code.