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//program to create macros using #define directive #include<iostream.h> #include<conio.h> #define PI 3.14 #define squarearea(a) a*a //macro to calculate area of square #define circlearea(r) PI*r*r #define sum(a,b,c) a+b+c void main() { clrscr(); int a=10; cout<<squarearea(a); cout<<"\n"; cout<<circlearea(a); cout<<"\n"; cout<<sum(a,a,a); getch(); }