write a class Circle with one double data radius . write motheds :::
public Circle(),public Circle (double),public Circle (Circle c)
public double getRadius()
public setRadius (double)
public getPerometer(int)where the parameter indicates the number of terms for π
public getArea (int) where the parameter indicates the number of term for π
public String toString ()
public Boolean equals( Circle c)
private double getpi(int) which returns the value of π corresponding to the specified number of terms ..
...finally test your class in main

``````/**
* @(#)Circlee.java
*
*
* @author
* @version 1.00 2011/10/17
*/

public class Circlee {
private double raduis;
public Circle(){
raduis=1;
}
public Circle(double rad){
raduis=rad;
}

public String toString(){
return 	"("+raduis+")";

}

}

}``````

if you can help me to understand this question .plz
i realy need to understand because i have tommorow exam and its will help me ..
all thanks ...

## Recommended Answers

First of all, use capital letters to ask questions and write normal sentences.
Your question in terms of steps, I am not on a write your code for you.
- Make all the methods in your class, empty.
- Think of what each method should actually do (e g the …

Are you a native English speaker? You write radius with i-u... (doesn't really matter)

Where do you get an error? Which line? And do far it looks good. Just keep going like this, and use your logic.

## All 8 Replies

First of all, use capital letters to ask questions and write normal sentences.
Your question in terms of steps, I am not on a write your code for you.
- Make all the methods in your class, empty.
- Think of what each method should actually do (e g the method getRadius, should return the radius).
- Write perimeter in stead of perameter.
- Use a general form for writing your methods, like getPerimeter(), GetPerimeter() or getperimeter(), and use that throughout your entire program.

i have error with the type ..
can you correct me plz

``````public class Circle {
private double raduis;
public Circle(){
raduis =0.0;
}
public Circle (double rad){
raduis=rad;
}
public Circle(Circle c){
raduis=c.getRaduis();
}
public void setRaduis(double rad){
raduis=rad;
}
public double getRaduis(){
return raduis;
}
public int getPerimeter(int perimeter){
perimeter=2*(Math.PI)*(int)raduis;
return perimeter;

}
public int getArea(int area){
area=(Math.PI)*(int)raduis*(int)raduis;
return area;
}

}``````

Are you a native English speaker? You write radius with i-u... (doesn't really matter)

Where do you get an error? Which line? And do far it looks good. Just keep going like this, and use your logic.

``perimeter=2*(Math.PI)*(int)raduis;``
``area=(Math.PI)*(int)raduis*(int)raduis;``

because area is int and raduis is double ??
how i can write this step ....
private double getpi(int) which returns the value of π corresponding to the specified number of terms ..

Are you a native English speaker? You write radius with i-u... (doesn't really matter)

QUOTE]
actully no ..
i starting to learn english

OK, that's great, you're doing quite well so far :). I am just asking you to type with normal sentences and capital letters.

The problem with the area: Change the type of area and the return type of the method to double. Also, you do not need a input in the method getArea(). Only a return value.

``````public double getArea(){
return Math.PI*Math.pow(raduis,2); // You can return without making a variable.
}``````

Explanation: Every time you cast a double variable to int, you lose all the information behind the decimal point. So to return a double, and keep all the information you return as it is.
If you must return an int, use the following code:

``````public int getArea(){
return (int) (Math.PI*Math.pow(raduis,2));
}``````

If the area is 3.99237, the method will return 3.

``````public double getPerimeter( ){
return 2*(Math.PI)* raduis;
}
public double getArea( ){
return Math.PI*Math.pow(raduis,2);
}``````

public getPerometer(int)where the parameter indicates the number of terms for π
public getArea (int) where the parameter indicates the number of term for π
now the above method i wroted correctly ?

private double getpi(int) which returns the value of π corresponding to the specified number of terms ..
... is this mean to write private double Pi=3.14 ;

The code you wrote looks perfect to me.

The methods you have to make for your assignment seem a little stupid to me, I don't really understand their meaning.
The only idea I can come up with, is the number of decimals PI should have in the calculation. You could use the DecimalFormat class for that, I don't have any experience there, you should Google it.

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