### C program to print right angle triangle using number :

In this C programming tutorial, we will learn how to create a right angle triangle using numbers. Like below :

1 1 2 1 2 3 1 2 3 4 1 2 3 4 5

1. The height of the triangle is *5*.

2. For line *1* only *1* number is printed. For line *2*, *2* numbers are printed etc.

3. All the numbers are printed *serially* i.e. like *1 2 3 4 5 6…*

To solve this problem, we will use *two* loops. One outer-loop and one inner-loop. The outer-loop will run for *‘height’* number of times, where *‘height’* is the height of the triangle. In the above example, it is *5*. The inner-loop will run for *outer-loop position* number of times. For the first line, outer-loop position is *1* , so the inner loop will run *1* time. For the second line, it will run for *2* times etc. We will use the inner-loop to print the numbers. After the inner loop is completed, one new line will be printed at the end.

Let’s take a look at the program to understand it more clearly :

### C program :

#include int main() { //1 int height; int i,j; //2 printf("Enter height of the triangle : "); scanf("%d",&height); //3 for(i=1; i <= height ;i++){ //4 for(j=1; j <= i ; j++){ printf("%d ",j); } //5 printf("\n"); } }

### Explanation :

*The commented numbers in the above program denotes the step-number below :*

1. Create one integer variable *height* to store the user-input height of the triangle. *i,j* integers are used in the loop below.

2. Ask the user to enter the height . Save it in variable *height*

3. Start two *for-loops*. The outer loop will run for *height* number of times. It runs for *i* from *1 to height*.

4. The inner-loop will run for *i* number of times.

5. In the inner-loop, print the values serially.

6. After the inner-loop is completed, print one new-line.

### Sample Output :

Enter height of the triangle : 6 1 1 2 1 2 3 1 2 3 4 1 2 3 4 5 1 2 3 4 5 6 Enter height of the triangle : 10 1 1 2 1 2 3 1 2 3 4 1 2 3 4 5 1 2 3 4 5 6 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 10