Temperature

// This program asks the user for a Fahrenheit temperature, 
// converts the given temperature to Celsius,
// and displays the results.
//
// References:
// https://www.mathsisfun.com/temperature-conversion.html
// https://en.wikibooks.org/wiki/C%2B%2B_Programming

#include <iostream>

using namespace std;

double getFahrenheit();
double calculateCelsius(double);
void displayResult(double, double);

int main() {
    double fahrenheit;
    double celsius;
    
    fahrenheit = getFahrenheit();
    celsius = calculateCelsius(fahrenheit);
    displayResult(fahrenheit, celsius);
    
    return 0;
}

double getFahrenheit() {
    double fahrenheit;
    
    cout << "Enter Fahrenheit temperature:" << endl; 
    cin >> fahrenheit;
    
    return fahrenheit;
}

double calculateCelsius(double fahrenheit) {
    double celsius;
    
    celsius = (fahrenheit - 32) * 5 / 9;
    
    return celsius;
}

void displayResult(double fahrenheit, double celsius) {
    cout << fahrenheit << "° Fahrenheit is " 
        << celsius << "° Celsius" << endl;
}

Output

Enter Fahrenheit temperature:
 100
100° Fahrenheit is 37.7778° Celsius

References

• Wikiversity: Computer Programming