We can use below C++ program to find out the largest number among three numbers.
#include <iostream>
using namespace std; int main() {
float First_Number, Second_Number, Third_Number;
cout << "Enter three numbers: ";
cin >> First_Number >> Second_Number >> Third_Number;
if((First_Number >= Second_Number) && (First_Number >= Third_Number))
cout << "Larger number: " << First_Number;
else if ((Second_Number >= First_Number) && (Second_Number >= Third_Number))
cout << "Larger number: " << Second_Number;
else cout << "Larger number: " << Third_Number;
return 0;
}