Need Help With This :(

[josemdc1202]

Iv'e been trying to solve this for a couple of days now and i cant seem tosolve it.




Joe’s Pizza Palace needs a program to calculate the number of slices a pizza of any size can be divided into. The program should perform the following steps:


Ask the user for the diameter of the pizza in inches.

Calculate the number of slices that may be taken from a pizza of that size.

Display a message telling the number of slices.


To calculate the number of slices that may be taken from the pizza, you must know the following facts:


Each slice should have an area of 14.125 inches.

To calculate the number of slices, simply divide the area of the pizza by 14.125.

The area of the pizza is calculated with this formula: Area = "pi r squared" where pi is approximately 3.14159 and r is the radius (half the the diameter).

[Hengry]

Do you have any code done? If you do, mind pasting your code here?

[keskiverto]

How would you:

Ask the user for the diameter of the pizza

calculate radius from diameter

calculate the area of the pizza

divide the area of the pizza by 14.125

Display a message telling the number of slices

[josemdc1202]

This is so far what I have. Thank you for the response.



#include <iostream>
#include <iomanip>
using namespace std;

int main() {
const double PI = 3.14159;
const double SLICEAREA = 14.125;
double diameter;
double r; // radius

cout << "Enter pizza diameter: ";
cin >> diameter;
r = diameter/2.0;
cout << ( static_cast<int>((PIrr)/SLICEAREA)) << " slices" << endl;
return 0;
}

[josemdc1202]

I keep getting these "compiler error" messages.


./ETest.cpp: In function ‘int main()’:
./ETest.cpp:14:29: error: ‘PIrr’ was not declared in this scope
cout << ( static_cast<int>((PIrr)/SLICEAREA)) << " slices" << endl;
^

[mbozzi]

Change PIrr to PI * r * r

Multiplication is not implicit; in order to multiply you need to supply the multiplication operator, *.

The problem is that the compiler is looking for a single symbol named PIrr, which doesn't exist or isn't visible -- it was "not declared in this scope".

Now is the time to point out that ^ doesn't represent exponentiation but instead bit-wise exclusive-or. Don't confuse them.