What is Curved Surface?
The curved surface is a rounded surface that is not flat.
| Curved Surface | Flat Surface |
 |  |
An object can have a curved surface all around it. Such objects have only one surface throughout. Examples of objects with the curved surface all around are spheres.
Real life examples of the objects with curved surface throughout are balls, globe, eggs, pipes, domes, etc
 Egg |  Ball |
There are 3D shapes that consist of only flat surfaces. For example, a cube, cuboid, pyramid and prism are all 3D shapes that are made up of flat surfaces. Their surfaces are squares, rectangles, triangles and parallelograms. None of them has a curved surface. The non-examples of 3D shapes with the curved surface are cubes, cuboids, pyramids, prisms, bricks, etc.
 Pyramid |  Cube |
3D shapes such as cones and cylinders have a curved surface as well as flat surfaces.
A cylinder has 2 flat surfaces and one curved surface.
A cone has one flat surface and a curved surface.
Examples of the objects with curved as well as flat surfaces are drums, cans, cones, etc
 Can |  Cone |
There are objects that can have 2 different curved surfaces. The given image shows a test tube with a curved surface (wall: cylindrical) and a curved surface for the base (spherical) too.
| Fun Facts 1. Multiple circles stacked together form a curved surface. 2. Any point on a curved surface is equidistant from its centre and this distance is called the radius. 3. A flat surface can be rolled to form a curved surface, and if you open a roll, you can get a flat surface. |
