Lancet arch

Imagine drawing a big rainbow-shaped line on a piece of paper with a pencil. Now, imagine that you could take that piece of paper and curve it around into a cylinder shape, kind of like a piece of pasta that you've rolled up. If you looked at the curved paper from the side, you would see that it makes a shape that looks like the letter "n".

This "n" shape is called a lancet arch. It's a type of arch that was popular in fancy buildings a long time ago, like big cathedrals and castles. The shape of the lancet arch is important because it makes the building look really tall and grand, but it also helps support all the weight of the building's walls and roof.

So, if you ever see a big old building with a bunch of fancy arches in it, there's a good chance that some of them might be lancet arches. They might look like rainbows or big church windows, but they're really just shapes that help make the building look cool and stay standing up.