Example · High school
Terms
| Term | This example | Why |
|---|
| connected |
✓ |
|
| path connected |
✓ |
The annulus is path-connected, and so connected, because every two points can be joined by a path that goes around the ring.
|
| simply connected |
✗ |
A loop around the hole cannot be shrunk to a point without leaving the ring.
|
| convex set |
✗ |
The annulus is not convex, because the segment between $(-1.5, 0)$ and $(1.5, 0)$ passes through the hole at the origin.
|
Distinctions using this example
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