Press "Enter" to skip to content

Find Area of a Rectangle, Circle and Triangle in C++ with Class Diagram

Finding area of circle, rectangle and triangle is a common basic question in all most programming languages. Here let’s solve the question together.

Manually we can find the area of a rectangle by using equation:
Area = Breadth * Length.

Also we can find the area of a circle by using equation:
Area = 3.14 * (radius)2

Also we can find the area of a triangle by using equation:
  Area = sqrt(s*(s-a)*(s-b)*(s-c))
a = length of first side
  b = length of second side
  c = length of third side
  s = (a + b+ c)/2

-where sqrt stands for square root

Class Diagram

 Class Name: areacalc
Data members:     
    arr[MAX]:int     
    count:int
Methods:       
 area(float)
         area(int,int)
         area(float,float,float)

Program Code

#include<math.h>
#include<iostream.h>
#include<conio.h>
class areacalc
{
  private:
  public:void area(float r);
  void area(int a,int b);
  void area(float a,float b,float d);
};
void areacalc::area(float r)
{  
 cout<<"Area of Circle="<<(3.14*r*r);
}
void areacalc::area(int a,int b)
{ 
 cout<<"\n Area of Rectangle="<<(a*b);
}
void areacalc::area(float a,float b,float c)
{ 
 float s,ar;
 s=(a+b+c)/2;
 ar= sqrt(s*(s-a)*(s-b)*(s-c));
 cout<<"\nArea of Triangle="<<ar;
}
void main()
{ 
 clrscr();
 areacalc ac;
 int r,a,b,c,d;
 cout<<"\n Choose your option";
 cout<<"\n...............................\n 1-rectangle\n 2-circle\n 3-triangle";
 cout<<"\n Enter your choice :";
 cin>>c;
 switch(c)
 {
   case 1:cout<<"\n enter breadth and length:";  
    cin>>a>>b;  
    ac.area(a,b);  
    break;
   case 2:cout<<"\n enter the radious of circle:";  
    cin>>r;  
    ac.area(r);  
    break;
   case 3:cout<<"\n enter  the three side of triangle:";  
    cin>>a>>b>>d;  
    ac.area(a,b,d); 
     break;
   default:cout<<"invalid choice";
   }
 getch();
} 

Sample Output

Choose your option
..............................
1-rectangle
2-circle
3-triangle
Enter your choice : 1
Enter Breadth and Length : 10
20
Area of rectangle = 200
C++ Program to Find Area of a Rectangle, Circle and Triangle with Class Diagram
15

Be First to Comment

Leave a Reply

Your email address will not be published. Required fields are marked *