3. (Constructor 15 Points) We declare the following class, where the constructors are missing. Please add the following three constructors in the rectangle class and implement the constructors. .The first constructor takes no input parameters. The height and width are set to 3 and 4, respectively member is set to height value; the width member is set to 4 class rectangle int height; int width; // A simple class public: // the first constuctor, // the second constuctor, // the third constuctor rectangle (void) // this is a destructor