Eccentricity (mathematics)

Eccentricity is like measuring how squished a circle or an oval is. Imagine you draw a circle and then you stretch it out longer. The distance between the center of the circle and the edge gets longer and longer as you stretch it out. This distance is called the "major axis," and the distance from the center to the edge at a right angle to the major axis is called the "minor axis."

Now, if you look at the circle and compare it to the stretched-out oval, you can see that the circle is perfectly round, while the oval is not. The amount that the oval is not round (or perfect), is what we call its eccentricity. The closer the eccentricity is to 0, the more round or circular the shape is. The closer it is to 1, the more stretched out or oval-like it is. It's like rating how much a shape is squished, with 0 meaning not at all and 1 meaning completely squished.

Mathematically, we can find the eccentricity of an oval by taking the square root of 1 minus (the length of the minor axis squared, divided by the length of the major axis squared). But remember, this is just a fancy way of measuring how squished a shape is!