Pythagoras Triangle

This the work Pythagoras, referred to as his triangle. This can be useful when solving Binomial expansion problems. This as well can be better explained by using combination and permutation.
The first thing you notice is that it starts and ends with one while in between are the addition of numbers; the addition 1 & 1 gives 2 on the 3rd line 2+1=3 and 2+1=3, then on the forth line 3 +1 =4  3+3=6. 3+1=4 it follows this pattern.