Sorting 2-D and 3-D shapes
Compare and sort common 2-D and 3-D shapes and everyday objects by their properties
What a learner can do afterwards
- Sort a collection of 2-D shapes by number of sides
- Sort 3-D shapes by number of faces or whether faces are flat/curved
- Explain criteria used to sort a group of shapes
1 · Read
Sorting means putting things into groups because they share something. You already know that flat shapes have sides and corners, and solid shapes have faces. To sort shapes, pick one thing to check, like the number of sides or the number of faces, then put the shapes with the same answer together.
Leo has a bag of flat shapes: two circles, three triangles, and two squares. He sorts them by counting sides. Circles have no straight sides, so they go in one pile. Triangles have 3 sides, so they go in another. Squares have 4 sides, so they get their own pile too.
Now think about solid shapes. A cube has 6 faces, and every face is flat, so it goes in the flat-faces group. A ball is curved all over and has no flat faces at all, so it goes in the curved group. A can has 2 flat faces on its ends and a curved side around the middle, so it has both kinds.
When you sort shapes, say your rule out loud, like 'these all have 4 sides.' That way anyone can check your groups and get the same answer.
Pick one thing shapes share, like sides or faces, then group them by that rule.
More to read
Polygons review
2D shapes are flat. Circles are round with no straight sides. Polygons have straight sides only.
Count sides to sort them. Three sides means triangle. Four sides can be a square or a rectangle. More sides need new names.
Identifying quadrilaterals
Shapes have sides and corners. Count the straight sides to name them. Triangles have 3, squares have 4.
Look for right angles too. A square has four right angles. A rectangle has four as well, but its sides can be long and short.
Attributes of 2D Shapes
2D shapes are flat. Circles are round with no straight sides. Polygons have straight sides only.
Count sides to sort them. Three sides means triangle. Four sides can be a square or a rectangle. More sides need new names.
Shape Attributes
Every shape has clues. Count sides, corners and faces. Look for round or flat parts.
Use the clues to sort. Put shapes with the same number of sides together. Then explain your rule to a friend.
Explore more
2 · Watch
En anglaisTake it off screen
Where it sits
This opens up
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.