# Rectangular Box 1

## Contents

### Age

3-5 years

### Materials

Four isosceles right triangles, equal in size. Two green triangles with black lines on the hypotenuse, and two yellow triangles with black lines on the equal sides. Six scalene right triangles equal in size. Two grey triangles with a black line on the hypotenuse. Two green triangles with a black line on the longer side that describes the right angle. Two yellow triangles with a black line on the shorter side that describes the right angle. Two yellow equilateral triangles with a black line on one side. One red scalene right triangle with a black line on the longer side that describes the right angle. One red scalene obtuse triangle with a black line on the side opposite the obtuse angle.

### Preparation

### Presentation

- Invite the child to work with the 'rectangular box'.
- Show the child where the rectangular box is located on the shelf. When the child has made the selection of the material, begin with the third step after naming the material for the child.
- Indicate the procedure for carrying the material: one hand on each side of the rectangular box with thumbs on top and fingers on the bottom.
- Place the box in the upper left side of the rug.
- Remove the lid and place to the right of the box.
- Say, "I will make shapes from the triangles."
- Remove from the box the two green and two yellow isosceles triangles one at a time and place them in a straight line at the bottom of the rug. With the index and middle fingers, trace the black lines on the green triangles. Slide them together, forming a square. Move the square below the rectangle box. With the index and middle fingers, trace the black lines on the yellow triangles. Slide them together, forming a rhomboid. Move the rhomboid to the right of the square.
- Select from the box ,the two grey, two green, and two yellow scalene right triangles one at a time and place them in a straight line at the bottom of the rug. Trace the black line on the grey triangles. Slide them together, forming a rhomboid. Trace the black line on the yellow triangles. Slide them together, forming a rhomboid.
- Select from the box the two yellow equilateral triangles and the red scalene triangles one at a time and place them in a straight line at the bottom of the rug. Trace the black line on the two yellow triangles. Slide them together, forming a rhombus. Trace the black line on the red triangles. Slide them together, forming a trapezoid.
- Replace the material into the box beginning with the trapezoid to the lower left, rhombus in upper left, right angle triangles in right as rectangles, and isosceles triangles as a square.
- Return the material to the shelf in the manner as indicated in #3.

### Control Of Error

Visual. Black guidelines and colored triangles.

### Points Of Interest

Touching and mapping black lines. Mixing and pairing the triangles. Working with an increasingly larger assortment of triangles. Naming the equilateral figures formed by the triangles.

### Purpose

- To show the equilateral figures formed by various triangles.
- Refinement of perception.
- Development of concentration, order, coordination, and independence.
- Respond to the sensitive need for order in the child.
- Preparation for geometry.
- Appreciation of line and form.
- Development of creativity.

### Variation

- Remove all triangles at one time and make the figures in presentation 1
- Trace the figures on construction paper and cut them out. Then paste the variations on paper and make a booklet.
- Trace the figures on construction paper and cut them out. Then paste the variations on poster board for charts.
- Look for the figures formed in the environment, in material, floor patterns, etc.
- Label the various figures.

### Links

### Handouts/Attachments