Question

A triangular number is the sum of the n natural numbers from 1 to n.

For example:

• The triangular number for 3 is 1 + 2 + 3 = 6
• The triangular number for 7 is 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28

Write a program segment (using a loop), that calculates and then prints the integer n and its triangular number.

Answer 1

Source Code:

Output:

Code in text format (See above images of code for indentation):

#include <iostream>
using namespace std;
/*main function*/
int main()
{
   /*varibles*/
   int n,i,tnum=0;
   /*read n value from user*/
   cout<<"Enter n value: ";
   cin>>n;
   /*using loop calculate triangular number*/
   for(i=1;i<=n;i++)
       tnum+=i;
   /*print number and triangular number*/
   cout<<"The number n is: "<<n<<" and its triangular number is "<<tnum;
return 0;
}