Derive the cube class from the base square class. Assume the square class has a protected member variable representing the side called side and declared as a double with a default value of 1.0. It also has a public function called calcVal that evaluates the area of a square as side * side. In your derived class have the default values for side be 1. For the cube class include a public function calcVal that evaluates the volume of the cube. (Hint: The volume of the cube is side * square :: calcVal.)