QBASIC PROGRAM TO FIND AREA OF CIRCLE

 CLS
 INPUT “ENTER RADIUS”; R
 A = 3.14 * R ^ 2
 PRINT “AREA OF CIRCLE ”; A
 END

USING SUB

DECLARE SUB AREA(R)
 CLS
 INPUT “ENTER RADIUS”; R
 CALL AREA(R)
 END
 
 SUB AREA(R)
 A = 3.14 * R ^ 2
 PRINT “AREA OF CIRCLE ”; A
 END SUB