1 3 6 10 15 21 28 36 45 55 Here is the list of triangular numbers. I wonder what happens when you add consecutive triangular numbers. That must give some kind of pattern. Kareem

I can’t see anything yet. 1 3 6 10 15 21 28 36 45 55 I can’t see anything yet. 1+3= 4 3+6= 9 6+10= 16

Let’s combine the first and second triangular numbers.

Let’s combine the second and third triangular numbers.

Let’s combine the third and fourth triangular numbers.

(n+1)th triangular number

144 dots in total 81 dots in total n 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Δ 𝑛 21 28 36 45 55 66 78 91 105 120 136 144 dots in total 81 dots in total

64 dots in total 256 dots in total n 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Δ 𝑛 21 28 36 45 55 66 78 91 105 120 136 64 dots in total 256 dots in total