A circle is strictly defined as living on a flat 2D plane in Euclidean geometry. But in spherical geometry, you can draw a perfectly valid circle on the surface of a globe, and the circle isn’t technically flat since the surface itself is curved in 3D space.
Can a circle not be flat?
A circle is strictly defined as living on a flat 2D plane in Euclidean geometry. But in spherical geometry, you can draw a perfectly valid circle on the surface of a globe, and the circle isn’t technically flat since the surface itself is curved in 3D space.