Area and Para of Rectangle

In this program, # is a preprocessor directive ,  whereas #include<filename.h> is used

to extract the functions already created in file .float a,b creates float type variables

which stores length & breadth of square given by user . area of rectangle = length*breadth

& perimeter of rectangle = 2*(length+breadth) which are stored in ar & peri respectively .  

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Program for Rectangle Area and Parameter.

#include<stdio.h>
#include<conio.h>
void main()
{ float ar,peri,a,b;
clrscr();
printf("\n program to calculate area & perimeter of rectangle");
printf("\n\n enter side1 of rectangle : ");
scanf("%f",&a);
printf("enter side2 of rectangle : ");
scanf("%f",&b);
ar = a*b;
peri = 2*(a+b);
printf("\n area of circle = %f",ar);
printf("\n perimeter of rectangle = %f",peri);
getch();
}