Geometry
Cylinders – Two Circles Joined by a Curved Surface
A cylinder is a solid with two identical, parallel flat circular faces, joined by one curved surface that wraps all the way around. Unlike the flat-faced solids you've just met (cubes, cuboids, prisms, pyramids), a cylinder has no straight edges connecting its two circular ends – and because it has no sharp corners at all, it has zero vertices.
You can think of a cylinder as a “circular prism” – it behaves just like a prism (uniform cross-section along its length), except its cross-section is a circle rather than a polygon, so the usual prism face/edge/vertex-counting rules don't quite apply the same way.
Properties of a Cylinder
A cylinder has 2 flat circular faces, 1 curved surface, 2 edges (where the curved surface meets each circle), and 0 vertices.
A cylinder has no sharp corners at all: 0 vertices.
Real-Life Application
- Cans: soft drink and food cans are cylinders.
- Pipes: plumbing and drainage pipes are cylindrical.
- Batteries: most household batteries are cylinder-shaped.
Key Takeaways
- A cylinder has 2 flat circular faces and 1 curved surface.
- It has 2 edges and 0 vertices.
- A cylinder behaves like a “circular prism.”