Ctrl+k

Describe 3D objects by flat and curved surfaces

Three-dimensional objects are described by the types and arrangements of surfaces that bound them: flat surfaces, or faces, and curved surfaces. Familiar solids such as cubes, cuboids, cylinders, cones, and spheres can be compared by these features, including recognizing that some have only flat or curved surfaces while others have both; formal measurement, nets, and advanced classification by edges and vertices are not included.

Detailed Explanation: Describe 3D objects by flat and curved surfaces

A 3D object is a solid shape. Look at the surfaces that make up its outside:

  • A flat surface is smooth and level, like the side of a box.
  • A curved surface bends, like the outside of a ball.

Example: Describe a cylinder

Imagine a soup can.

  1. Look at the top. It is a flat circular surface.
  2. Look at the bottom. It is another flat circular surface.
  3. Look around the side. It bends all the way around, so it is curved.

So, a cylinder has:

  • 22 flat surfaces
  • 11 curved surface

We can describe it by saying:

A cylinder has two flat surfaces and one curved surface.

Learn by doing: Describe 3D objects by flat and curved surfaces

Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill

    Practice with unlimited practice problems

    3D Shape Surfaces - Has Flat/Curved Surface to Shape

      ?