Latitudes are parallel to the equator but are not of the same size because the Earth is not a perfect sphere, it bulges at the equator and flattens at the poles. As a result, the distance around the Earth is greater at the equator than at the poles. This means that circles of latitude become smaller as they get closer to the poles. Therefore, latitudes are parallel to each other but their size decreases as they move away from the equator toward the poles.
