声明一个Rectangle类，有长itsWidth、宽itsLength等属性，重载其构造函数Rectanle()和Rectangle(int width，int length)。填空完成下面程序。#includeclass Rectangle{public:(1);Rectangle(int width,int length);~Rectangle(){ }int GetWidth() const{ return itsWidth;}int GetLength() const{ return itsLength;}private:int itsWidth;int itsLength;};Rectangle::Rectangle(){ itsWidth=5;itsLength=10;}Rectangle::Rectangle(int width,int length){(2);(3);}void main(){ Rectangle Rect1;cout<<"Rect1 width:"<>aWidth;cout<<"\nEnter a length";cin>>aLength;Rectangle (4);cout<<"\nRect2 width:"<