Thread: Deriving one class from another

Ok, yeah, it's homework. Here's the deal, I need to make a class "point", perform operations on the point, like showing the point, setting and printing coordinates, and showing x and y coordinates, then... design a class "circle" that can sotre radius and center and derive "circle" from "point" to perform operations on a circle, like setting radius, printing the radius, calculating and printing the area and circumference and such.

Here is what I've done so far:

circle.cpp

Code:

#include <iostream.h>
#include <math.h>
#include "Circle.h"

void Circle :: read() {
    cout << "\nEnter radius of circle: ";
    cin >> radius;
    cout << "Enter center point of circle:";
    Point::read();
}
float Circle :: area() const {
    const float pii = 3.14159;
    return  pii * radius * radius;
}
void Circle :: I_am() const {
    cout << "\nI am Circle ";
}

Circle.h

Code:

#ifndef _circle
#define _cicle
#include "point.h"
class Circle : public Point{
    private:
        float radius;
   public:
        void read();
        float area() const;
        virtual void I_am(void) const;
};
#endif

point.cpp

Code:

#include <iostream.h>
#include <math.h>
#include "point.h"

void Point::read() {
    cout << "\n Enter x-coordinate of point: ";
    cin >> x;
    cout << " Enter y-coordinate of point: ";
    cin >> y;
}

float Point :: area() const{
    return 0.0;
}
void Point :: I_am() const {
    cout << "\nI am Point ";
}
float Point::distance(const Point &p2)const{
    return sqrt( (p2.x-x)*(p2.x-x) + (p2.y - y)*(p2.y - y));

}

point.h

Code:

#ifndef _point
#define _point
#include "shape.h"
class Point : public Shape {
    public:
      virtual void read();
      virtual float area() const;
      virtual float distance(const Point &p2)const;
      virtual void I_am() const;
    private:
      float x;
      float y;

};
#endif

Then I wrote an abstract

shape.h

Code:

#ifndef _shape
#define _shape
class Shape {
    public:
        virtual void read() = 0;
        virtual float area()const = 0 ;
      virtual void I_am() const = 0;
};
#endif

Now, i'm getting an error:

point.pp
Cannot open include file: 'iostream.h': No such file or directory
circle.cpp
Cannot open include file: 'iostream.h': No such file or directory


Any help is appreciated.
Thanks

From 17.4.3.1.2
- Each name that contains a double underscore (__) or begins with an underscore followed by an uppercase letter is reserved to the implementation for any use.

Technically, _point is ok.