This is a C++ program to find area of a rectangle, circle and triangle. Class diagram of program also given below.

Manually we can find the area of a

**rectangle**by using equation:

Area = 3.14 * (radius)

^{2}^{}

**triangle**by using equation:

a = length of first side

b = length of second side

c = length of third side

s = (a + b+ c)/2

b = length of second side

c = length of third side

s = (a + b+ c)/2

Area = sqrt(s*(s-a)*(s-b)*(s-c))

-where sqrt stands for square root

-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

## Responses

1 Respones to "C++ Program to Find Area of a Rectangle, Circle and Triangle with Class Diagram"Thanks a lot...

October 10, 2012 at 12:19 AM

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