Montessori Constructive Triangles + DIY Printable

Table of Contents

What are the Montessori Constructive Triangles?
Presentation

What are the Montessori Constructive Triangles?

The Constructive Triangles offer children hands-on exposure to concepts in plane geometry. The materials include two rectangular boxes, a triangular box, a small hexagonal box, and a large hexagonal box, each housing triangles of varying sizes, forms, and colors.

Through the use of Constructive Triangles, children learn the relationships between triangles and how they make-up other two-dimensional shapes.

Material

– Rectangular Box A (14 pieces)
– Rectangular Box B (8 pieces)
– Blue Rectangular Box (12 pieces)
– Triangular Box (10 pieces)
– Small Hexagonal Box (18 pieces)
– Large Hexagonal Box (11 pieces)

You can use printable DIY alternative HERE.

Prerequisite

– Geometry cabinet and language

Control of Error

– The triangles have black lines which should be connected with another to make a different plane figure.

Direct Aims

This helps the child create different shapes from triangles, build their spatial orientation and attention to detail. This also allows the child to learn that all plane figures with straight lines are made up of triangles.

Indirect Aims

Additionally, this indirectly prepares the child for finding area and the equivalence of different shapes.

GET the DIY ALTERNATIVE here

Presentation

Watch the following videos (click the hyperlinked texts) to learn how to present the lessons:
- Rectangular box A
  - Work with 2 yellow equilaterals, 2 gray right-angled scalenes, and 2 green right-angled isosceles (match, superimpose, and align black lines to make a shape)
  - Work with 2 yellow right-angled isosceles, 2 yellow right-angled scalenes, and 2 green right angled scalene triangles (do the same as i)
  - Work with the remaining red triangles and form a shape.
- Triangular box
  - Work with green triangles (superimpose and put the black lines together)
  - Repeat with yellow triangles, then with the red triangles.
  - Do the same with the gray triangles.
  - Language lesson: Base, vertex, altitude/height (with the gray triangles), center of the triangle (with the yellow triangle), midpoint of the triangle (with the red and gray triangles)
- Large hexagonal box
  - Form a rhombus with the red triangles; then form a parallelogram with the gray triangles
  - Form a hexagon with yellow triangles with one line each and the large triangle
  - Form a triangle with the yellow triangles with two lines each
  - Superimpose the triangle on the inner triangle of the hexagon, then show the child each rhombus formed by sliding them away, forming 4 rhombuses
- Small hexagonal box
  - Form a rhombus with the red triangles, then form a trapezoid with the green triangles, then form a hexagon with the gray triangles.
  - Show the child that the gray hexagon can be split into three rhombuses and superimposes the red rhombus.
  - Ask the child to reform the hexagon then show that it can be split into two trapezoids and superimposes on the green trapezoid.