Building with 3-D Shapes
Compose three-dimensional shapes (cubes, right rectangular prisms, right circular cones, right circular cylinders) and create composite shapes; build new shapes from component shapes
What a learner can do afterwards
- Stack cubes and prisms to build towers or structures
- Combine 3-D shapes to make a new solid (e.g. cone on top of cylinder)
- Describe a composite 3-D shape in terms of its component shapes
1 · Read
You already know cubes, cones, cylinders, and prisms. Now you can put two or more of them together to build something new. A shape made from smaller shapes is called a composite shape.
Mia builds a rocket. She stands a cylinder up tall for the body, then sets a cone on top for the nose. The new shape is a composite shape made from a cylinder and a cone.
Cubes and rectangular prisms have flat faces, so they stack well. Line up the flat top of one shape with the flat bottom of the next, and the tower stands steady. A cone balanced on its point tips over easily.
When you describe a composite shape, name each piece and where it sits. A toy robot might be a cube head on a rectangular prism body, standing on two small cubes for feet.
A composite shape is built from two or more 3-D shapes, and you can always describe it by naming its parts.
More to read
Geometry: FAQ
Shapes are sorted by their parts: sides, corners, and faces. Flat shapes like triangles and squares live on paper, while solid shapes like cubes and balls fill space. Counting parts is the fastest way to name a mystery shape. Every face of a solid is itself a flat shape. Learn the faces and the solid gives itself away.
10.2: Solid
Solid shapes take up space and wear flat faces, sharp edges, and pointy corners. A cube shows six square faces, twelve edges, and eight corners. Cones and cylinders add smooth curved faces to the mix. Describe any solid by naming its faces, then counting edges and corners. Building with blocks teaches these parts by touch.
Section 4: Polygons
Polygons are flat closed shapes with straight sides, and solids are built from these flat faces. Stacking boxes piles face on face, which is why towers of cubes stand tall. New solids grow by joining parts: a cone on a cylinder becomes a rocket, and a pyramid on a cube becomes a house. Name each part, then describe how they join.
Explore more
2 · Watch
En anglaisTake it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
18 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.