Question

Write a program in QBASIC that asks radius of a circle to calculate its area and circumference. Create a user-defined function to calculate area and sub-program to calculate circumference. [HINTA = T C = 2nr]​

Answer 1

Here's a QBASIC program that asks for the radius of a circle, calculates its area using a user-defined function, and calculates its circumference using a sub-program:

```

REM Circle Area and Circumference Calculator

CLS

REM Define user-defined function to calculate area

DEF FNarea(r)

area = 3.14159 * r * r

FNarea = area

END DEF

REM Define sub-program to calculate circumference

SUB CalcCircumference(r)

circumference = 2 * 3.14159 * r

PRINT "Circumference: "; circumference

END SUB

REM Ask for radius input

INPUT "Enter the radius of the circle: ", r

REM Calculate and print area using user-defined function

area = FNarea(r)

PRINT "Area: "; area

REM Calculate and print circumference using sub-program

CALL CalcCircumference(r)

END

```

In this program, the user-defined function `FNarea` calculates the area of the circle using the formula `area = pi * r^2`. The sub-program `CalcCircumference` calculates the circumference of the circle using the formula `circumference = 2 * pi * r`. The `INPUT` statement asks the user to input the radius of the circle. The program then calculates and prints the area and circumference of the circle using the user-defined function and sub-program.