Problem Analysis:
This program will calculate the area or perimeter of a rectangle whose dimensions are provided by the user. I will use integer variables, float variables, selection statements, a loop, and functions in this program. “Option” and “Start” will be declared as integers, the float variables will be “length”, “width”, and “answer”. To find the area of a rectangle, I will use the equation area=length*width. To find the perimeter of a rectangle, I will use the equation perimeter=2(length+width).

Pseudocode:

BEGIN
// This program will calculate the area or perimeter of a rectangle whose dimensions are provided by the user.

SET area and perimeter functions

//Declare Variables
DECLARE Option, Start as integer
DECLARE length, width, answer as float

WHILE Start >0
//Ask for user input
WRITE “Enter a positive number to calculate the area or perimeter.”
WRITE "To end this program enter 0 or a negative number.”
INPUT Start IF Start>0 WRITE "Enter 1 to calculate area or 2 to calculate the perimeter.” INPUT Option IF Option==1 WRITE "Please enter the length of the rectangle:" INPUT length WRITE "Please enter the width of the rectangle:" INPUT width SET answer=area(length,width) WRITE "The area of the rectangle is %.2f. " ELSE IF Option==2 WRITE "Please enter the length of the rectangle:" INPUT length WRITE "Please enter the width of the rectangle:” INPUT width WRITE "The perimeter of the rectangle is %.0f.” END IF ELSE WRITE "Invalid option, only 1 or 2 is accepted!” END IF

END

FUNCTION area( float length,float width) SET area=length*width
END FUNCTION

FUNCTION perimeter( float length, float width) SET perimeter=2*(length*width)
END FUNCTION

C Code

#include
#include

float area( float length, float width); float perimeter(float length, float width);

int main ()
{
//Declare variables int Option, Start; float length, width, answer;

//Start selection loop while (Start > 0) { printf ("Enter a positive number to calculate the area or perimeter.\n"); printf ("To end this program enter 0 or a negative number.\n"); scanf(" %d", &Start);

if (Start > 0) { printf ("Enter 1 to calculate area or 2 to calculate the perimeter.\n "); scanf(" %d", &Option);

if (Option==1) { //Area function printf("Please enter the length of the rectangle:\n"); scanf(" %f", &length); printf("Please enter the width of the rectangle:\n"); scanf(" %f", &width); answer=area(length, width); printf("The area of the rectangle is %.2f. \n", answer); }

else if (Option==2) { //Perimeter function printf("Please enter the length of the rectangle:\n"); scanf(" %f", &length); printf("Please enter the width of the rectangle:\n"); scanf(" %f", &width); answer=perimeter(length, width); printf("The perimeter of the rectangle is %.0f. \n", answer); }

else printf("Invalid option, only 1 or 2 is accepted!\n"); }

}

return 0;
}
//Code for area function float area( float length,float width)
{
return (length*width);
}

//Code for perimeter function float perimeter( float length, float width)
{
return (2*(length+width));
}

Test Data