简单java题我不会长方形类

Question

创建一个长方形的类，要求有两个属性，一个常高，一个宽，两个方法，，一个求面积，一个求周长。

Answer 1

public class Rectangle{
private double width;
private double height;
public Rectangle(){}
public Rectangle(double width){
this.width = width;
}
public Rectangle(double width,double height){
this.width = width;
this.height = height;
}
public double getArea(){
return width*height;
}
public double getPerimeter(){
return (width+height)*2;
}

}