BRIEF REVIEW OF CLASS o Base class Base class will be constructed first ·∥BallT is a derived class from ArcT ·/∥A ball is an arc of360 degree BallT (double r=0):ArcT (r,0,360,"Blue",1); o Constructors Always define a default constructor(suggested) One and only one of the constructors must be calledBRIEF REVIEW OF CLASS  Base class  Base class will be constructed first  // BallT is a derived class from ArcT  // A ball is an arc of 360 degree  BallT (double r = 0) : ArcT (r, 0, 360, "Blue" , 1) {};  Constructors  Always define a default constructor (suggested)  One and only one of the constructors must be called