constructive triangles box 1

This sensorial lesson is designed for 3 to 6-year-old children. It introduces the child to constructive triangles box 1: rectangular box. This box is the first in the series of Constructive Triangles.

What is the Constructive Triangles Box 1: The Rectangular Box?

The Rectangle box of constructive triangles contains red, green, gray, and yellow-colored constructive triangles of different sizes. These triangles, when combined, form rectangles.

It is also called the first box of constructive triangles that is introduced to the child. It contains the following:

  • 2 small equilateral triangles with black lines along with one of the edge
  • 2 right-angle isosceles triangles with black lines along the hypotenuse
  • 2 yellow right-angle isosceles triangles with a black line along with one of the sides
  • 2 green right-angle triangles with black lines along the longer right-angled sides
  • 2 yellow right-angle scalene triangles with a black line along the shorter of the two right-angle sides
  • 2 grey right-angle scalene triangles with a black line along the hypotenuse
  • 1 red right-angle scalene triangle and 1 red obtuse angle scalene triangle

In this video lesson, the child learns about the different types of triangles and how they combine to form a rectangle. It also helps in developing a child’s muscle memory, order, and concentration. Such activities enable the child to practice fine motor skills and hand-eye coordination.

Watch the video to learn and form rectangles using constructive triangles. This sensory lesson is a fun, innovative way to help them develop a better understanding of math concepts.

To watch more videos on constructive triangles, visit:

  1. Constructive Triangles: Blue rectangle box or second rectangle box
  2. Constructive Triangles: Triangular Box
  3. Constructive Triangles: Small Hexagon Box
  4. Constructive Triangles: Large Hexagon Box

For more math resources, visit:

Video Created by: Bronia Birkbeck


  • English
  • Math
  • primary
  • sensorial