What are the constructive triangles in Montessori?
The constructive triangles are boxes of coloured triangles that children combine to make other shapes, such as rectangles, rhombuses, hexagons and larger triangles. Black guide lines on some edges show where pieces join. They teach that shapes can be built from triangles and prepare for later geometry.
What this means in practice
Children discover the relationships themselves, guided by the lines.
The boxes
- Triangular box
- First and second rectangular boxes
- Small and large hexagonal boxes
What children learn
Equivalence of shapes, properties of triangles and the vocabulary of geometry.
Practical next steps
- Present one box at a time.
- Show joining along black lines.
- Let children explore.
- Name new shapes.
ExampleTwo equilateral triangles join to make a rhombus; Noor shouts 'a diamond!' and the teacher introduces 'rhombus'.
What to keep in mind
These are advanced; offer after the geometric cabinet.
Common follow-up questions
What age?
About 4½–6.
How many boxes?
Usually five.
Sources
Examples are educational illustrations with made-up names. How these answers are prepared.