Kids are surrounded by shapes on a daily basis and love to interact with them. They talk about the shapes of cookies, puzzle pieces, and things they encounter outside as well, like swing sets or parts of bicycles. 

The more we direct their attention to these shapes the more they will adopt this practice into their routines. Getting kids to connect to those shapes is critical at an early age as it facilitates geometric learning later on in their scholastic career.

Another great introduction to this topic is by relating it to student’s lives.

Geometry is a part of many different professions, like architecture, interior design and engineering. If your child has already shown interest in shapes, studying these careers will come much easier to them. 

Another way to present this topic is through manipulatives and toys, like stacking blocks, magnetic plates, and ball games. Any activity that gets them thinking about shapes and how they work together is very helpful to turn abstract ideas into concrete words. 

Having a reference guide, like a flipbook or a set of Montessori 3-part cards allows them to connect images to labels. This helps them organize the new words in a logical way. 

Start with basic 2D shapes 

For example: when starting with 2D shapes, or polygons, have them collect objects from the house and see what shapes they already know. Then give examples of the most common shapes: circle, triangle, square and so on. They can be regular with equal sides and angles, or irregular with varied sides and angles.

Some ideas for 2D objects in the home:

  • A cookie
  • A book
  • A ruler
  • A jar lid
  • A coaster
  • Popsicle sticks
  • Rubber bands
  • A sponge
  • Buttons
  • Pillows
  • Leaves

Some of these can be cut into more unusual shapes to complete the cards. For example some cardboard coasters from a bar can be cut into pentagons or other multi-sided polygons, or sponges can be cut into trapezoids or parallelograms.

Once they have a basic understanding of the most common shapes introduce the language involved in these shapes like: height, width, side, angle, and vertex. Explain the definition of each and give examples. 

2D Activities:

The kids could draw the new shapes with crayons or cutting shapes into Playdoh to help deepen the learning. It’s important to make each set of shapes age-appropriate as the more irregular or complex a shape is the more complex the definition becomes.

So for a small child (1 to 3 yo) stick with the basic shapes: circle, triangle and square. For older kids, depending on developmental stage, more shapes can be added gradually. Below are the definitions you can give while explaining.

Definitions of some 2D shapes:

Polygons are shapes with many sides and their classification depends on the number of those sides.



All triangles have 3 sides.

Equilateral triangles have 3 equal sides and angles.


Isosceles triangles have 2 equal sides.


Scalene triangles have 0 equal sides.



Right triangles have a 90 degree angle.



Obtuse triangles have an angle with more than 90 degrees. 



Acute triangles have all angles of less than 90 degrees.




All quadrilaterals have 4 sides.



Squares have 4 equal sides and angles.


Parallelograms have 2 sets of parallel sides and the opposite angles are equal.



Rectangles have 4 right angles and the opposites sides are equal but have different heights or widths.



Trapezoids have 1 set of parallel lines but 2 different sets of angles.



Rhombuses have 4 equal sides and the opposite angles are equals but have 2 different degrees.



Various polygons:

These polygons can have sides with different lengths and angles. But what determines their classification is the number of sides they have, which is always more than 4.


5 sides: Pentagon



6 sides: Hexagon



7 sides: Heptagon



8 sides: Octagon



9 sides: nonagon



10 sides: decagon



Round shapes:

Shapes with curved sides.


Circles are round shapes with a curved line that completely encloses a space and is the same distance from the centre at every point.


Ellipses are shapes similar to a circle but longer than they are wide and have 2 symmetry axes.




Ovals can be an ellipse in shape but they can also have only one axis of symmetry, like an egg.





Using the 3-part cards and felt pieces


As I illustrated in the post How to teach vocabulary using Montessori 3-part cards, you should introduce new shapes with consistent clear language. Using our felt board and 3-part cards is the best way to include visuals to the lesson.

Take a pair of control cards, read one for them and define it (depending on their level): 


“This is a right triangle, it has three sides and one right angle, or 90 degrees. Can you say ‘right triangle?’”

Then do the same with the second card.

With the two cards laid next to each other, you say:

“Can you show me a right triangle?”

Then, do the same with the second card.

Next, you ask(pointing):

“What is this?” to each card.

Repeat this with three or four more pairs of cards. Then have them match the object and label cards. 

As a follow up activity, replace the object card with a felt piece and follow the instructions from the 3-part card article. Another expansion activity would be to replace the object card with the household objects from before.

Finding shapes in nature

Polygons appear everywhere in nature, sometimes without us even noticing. If you look closely you can find them in rock formations, on the beach with shells and seaweed, and very commonly as the flat facets of crystals. Fun fact: the angle between the sides depend on the type of mineral which the crystal is made from.


In some rare instances, and you can find more great pictures of this on the internet, regular hexagons are formed when the cooling of lava creates patches of tightly packed columns of basalt. Examples of this are at the Giant’s Causeway in Northern Ireland, or at the Devil’s Postpile in California.

But the most famous collection of hexagons is present on the surface of the wax honeycomb made by bees, and the sides and base of each cell are also polygons.





For little kids:


For bigger kids:


More activities to help with shapes:

[Disclaimer: As an Amazon Associate I earn from qualifying purchases at no cost to you from the affiliate links below]

Playmags are ideal for not only making pictures and forms but also amazing structures. This is the activity that paves the way for future architects!



Tangram sets allow kids to follow schematics and at the same time use their creativity to make any picture they want using the basic shapes learned in this lesson guide.





Legos need no introduction. They have perhaps been responsible for the shaping of some of the most incredible minds in the last 50 years. They have no limit to their learning influence both with with shapes and 3D structures.



Pattern blocks have two very important functions. The individual pieces can be used for object – card matching or as pieces to form fun shapes and pictures.




Geoboards also have the dual function of practicing shapes with rubberbands and fine motor skill practice for small fingers.




Playdoh and a collection of tools are great hands-on materials for shaping both 2 and 3D shapes. The cookie cutters can make instant shapes or they can cut them with the knife for more creative freedom.



Etch a sketch is a mechanical method for children to explore shape creation. It is both fun and ecological as no paper is used.


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