C++ Help

[o_O]

int main() {
    float choice;
    cout << "This will convert fahrenheit to celsius.";
    cout << "What do you want to start with, enter your number than print enter.\n";
    cout << " 1. Fahrenheit\n";
    cout << " 2. Celsius\n";
    cin >> choice;
    
    if (choice == 1) {
        float fTemp;
        cout << "Input temperature in fahrenheit: ";
        cin >> fTemp;
        cout << toCelcius(fTemp);
    else {
        float cTemp;
        cout << "Input temperature in celcius: ";
        cin >> cTemp;
        cout << toFahrenheit(cTemp);
    }
}

float toCelcius(float fTemp)
{
    return (fTemp-32)/1.8
}

float toFahrenheit(float cTemp);
{
    return (1.8*cTemp)+32;
}

This could be one way to do it by passing variables. You need to define the variable outside of the function in order to pass it too the function.