Week 2 Project 2: Define the abstract class shape, and then derive the circle (circle), rectangle (rectangle), and triangle (triangle)

/** Program Copyright and version description Section * copyright (c) 2012, Yantai University Computer college student * All rightsreserved. * Author: Li Yang * Completion Date: July 15, June 2, 2013 * version: V1.0 * input Description: none * Problem description:, define the abstract base class shape, which derives three Derived classes, circle, rectangle, and triangle ). * Program output: area of several ry and */# include <iostream> using namespace STD; Class shape {public: Virtual double area () const = 0; // define pure virtual functions}; Class circle: Public shape {public: Circle (Double R): radius (r) {} double area () const; private: double Radius ;}; double circle: Area () const {return (radius * 3.14);} class rectangle: Public shape {public: rectangle (double W, double H): width (W), height (H) {} double area () const; private: double width; double height ;}; double rectangle: Area () const {return width * height;} class triangle: Public shape {public: triangle (Double X, Double Y): WID (x), hei (y) {} double area () const; private: Double WID; double Hei;}; double triangle: Area () const {return 0.5 * WID * Hei;} int main () {circle C1 (12.6 ), c2 (4.9); // create a circle Class Object C1 and C2. The parameters are round radius rectangle r1 (4.5, 8.4), R2 (5.0, 2.5 ); // create rectangle class objects R1 and R2. The parameters are long rectangle, wide triangle T1 (4.5, 8.4), and T2 (3.4, 2.8). // create a triangle Class Object T1, t2, the parameter is triangle bottom side length and high shape * PT [6] ={ & C1, & C2, & R1, & R2, & T1, & T2 }; // define the base class pointer array PT so that each element points to a derived class Object double areas = 0.0; // areas is the total area for (INT I = 0; I <6; I ++) {areas = areas + Pt [I]-> area () ;}cout <"totol of all areas =" <areas <Endl; // return 0 ;}