The bounding rectangle of the circular area.
- iOS 4.0+
- macOS 10.9+
- Mac Catalyst 13.0+
- tvOS 9.2+
As latitude values move away from the equator and toward the poles, the physical distance between map points gets smaller. This means that more map points are needed to represent the same distance. As a result, the bounding rectangle of a circle overlay gets larger as the center point of that circle moves away from the equator and toward the poles.