ELI5: Explain Like I'm 5

Triangle roll

Imagine you have a piece of paper that is a perfect square, but you want it to become a triangle. In order to do that, you need to fold it in half diagonally, which means you fold one corner of the square over to the opposite corner. This creates a crease down the center of the paper, dividing it into two smaller triangles.

Now, to create a triangle roll, you need to roll up one of those smaller triangles very tightly. Start at the wide end of the triangle and roll it up like a spiral, making sure to keep it tight. When you reach the pointy end of the triangle, you'll have a small rolled-up shape that looks like a cone.

But wait, there's more! In order to make a triangle roll, you need to repeat this process with two more squares of paper. Once you have all three of your rolled-up triangles, you can arrange them into a larger triangle shape by placing them next to each other, with their flat sides touching.

Now you have a delicious triangle roll! Well, not really. That was just a craft project. But the same idea of rolling up a triangle can also be used to create certain types of pastry or sushi rolls that have a triangle shape. The end result is a tasty treat that's fun to eat and looks pretty cool too.