Why the length of a parallel increases as be move away from the poles?

The length of a parallel, or latitude line, increases as you move away from the poles because the Earth is shaped like an oblate spheroid, being slightly flattened at the poles and bulging at the equator. As you move towards the equator, the circumference of the Earth increases, resulting in longer parallels. This geometric relationship means that lines of latitude are closer together near the poles and farther apart near the equator, leading to the increased length of parallels away from the poles.