Euler characteristic of an orbifold

An orbifold is like a shape that is a little bit bendy or has some bumps on it. To figure out something about the shape of the orbifold, we use something called the Euler characteristic. Think of it like a special number that tells us how many corners and edges the orbifold has. We can calculate the Euler characteristic by subtracting the number of edges from the number of corners and adding one. This number can help us understand more about the shape of the orbifold, like how twisted or curved it is. So, it's like a special way of counting the corners and edges on a bendy shape so that we can learn more about it.