print the area of given figure in C ?

 #include<stdio.h>
 #include<conio.h>
 int main()
 {
	 int length,breadth,area;
	 printf("Enter the length and breadth of the rectangle :");
	 scanf("%d%d",&length, &breadth);
     area = length * breadth; 
     printf("area of rectangle is :%d",area);
     getch();
 }

Program Explanation

Step 1: include header files (#include<stdio.h> and #include<conio.h>).

Step 2: start with main function with return type.

Step 3: parenthesis to start and end the program { }.

Step 4: declare the variables with data types. i.e, values of 'length' and 'breadth' are of integer type so we declare 'length' and 'breadth' with "int" data type. We also declare 'area' as "int" because it returns an integer value.

Step 5: use output function printf() to print the output on the screen.

Step 6: use input function scanf() to get input from the user.

Step 7: using getch() function to hold the screen.

 #include<stdio.h>
 #include<conio.h>
 int main()
 {
	 float pi=3.14,radius,area;
	 printf("Enter the radius of circle :");
	 scanf("%f",&radius);
     area = pi * radius * radius; 
     printf("area of circle is :%f",area);
     getch();
 }