Hints:

1. Begin with a simpler version of the puzzle: try solving it with a triangle of 6 dots (with 3 dots on the bottom row).
   ➤ How does that smaller version behave? What patterns do you notice?

2. You’ll discover that removing just two dots is enough to make the triangle work in that case.
   ➤ Why only two? What does that tell you about the structure?

3. Now, take what you learned from the 6-dot triangle and apply that thinking to the 10-dot triangle.
   ➤ Can you spot a similar pattern or strategy that will help?