Program Abstraction:This article contains a simple C program to find the area of rectangle, circle and triangle.

Finding the area of rectangle, circle, or triangle is one of common questions in C practical examination. Finding the area of circle, rectangle and triangle may in a same question or question may ask you find area of anyone of above shape.

This is a C program to find area of a rectangle, circle and triangle in a same program. You can separate this program as your needs.

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

ØAlso we can find the area of a circle by using equation:

ØAlso we can find the area of a triangle by using equation:

IF:
a = length of first side
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

Program Code:

`#include <stdio.h>#include <conio.h> #include <stdlib.h> #include <math.h> void main(){int a,b,c,r, rectarea;float circlearea, s1,s2,s3;float s,triarea2;clrscr();printf("n Three Choices");printf("n…………………….n 1- rectanglen 2- circlen 3- triangle");printf("n Enter your choice :");scanf("%d",&c);switch(c){case 1:    printf("n Enter breadth and length of rectangle:");  scanf("%d%d",&a,&b);  rectarea = a * b;  printf("Area of rectangle with breadth %d and length %d is %d units",a,b,      rectarea);  break;case 2:printf("n Enter the radius of circle:");  scanf("%d",&r);  circlearea = 3.14 * r * r;  printf("Area of triangle with radius %d is %f units ",r, circlearea);  break;case 3:  printf("n Enter the three side of triangle:n");  scanf("%f%f%f",&s1,&s2,&s3);  s = (s1 + s2 + s3)/2;  triarea2 =sqrt(s *((s - s1) * (s - s2) * (s - s3)));  printf("Area of triangle is %f",triarea2);  break;default:  printf("Invalid choice");}getch();}`

Sample output for finding area of a rectangle with breadth and length 5 and 10 respectively:

Enter the breadth and length of rectangle:

5
10
Area of rectangle breadth 5 and length 10 is 50 units

Sample output for finding area of a triangle with the length of sides as 4, 5, and 6

Enter the length of the 3 sides of triangle:
4
5
6
Area of triangle is 9.921

Sample output for finding area of a circle with radius 3:

Enter the radius of circle : 3
Area of triangle with radius 3 is 28.260000 units

More C Examples