Polygon activity 3 decomposition and composition 2/2


Each pupil will receive 2 sheets of origami paper.
For this lesson, each pupil must have a red marker and the measurement tool ready. 
Spread the sheets and hand out 2 sheets to each pupil.
The measurement tool is described in the lesson, ‘A Measuring Tool for Comparison of Lengths’.


A discussion question:
What is the shape of the sheet in front of you?
In what way can we find out the correct name?
Explain..

We measure the sides of the square using the measurement tool.
The next slide should not be shown before the end of class discussion.


Answer:
The shape of the sheet is a square: 4 sides and 4 vertices.
With your measurement tool, check that all of the sides of the shape are equal in length and that the 4 angles at the vertices are rightangles.



Folding instructions:
Fold one vertex to lie on top of the opposite vertex. Do this with both sheets. 
It is suggested not to give any aid to the pupils with their own folding. The teacher should pay attention to the folding of the pupils in the classroom.


A discussion question:
What shape do you have now?How do you know?
Explain.


Answer:
We have a triangle shape. A triangle has 3 sides and 3 vertices..


A discussion question:
Join 2 triangle shapes in different ways.
Which polygons can you form?
Explain. 
Point out to the pupils that when joining the shapes, adjacent sides must be of the same length.


Answer:
When joining the 2 triangle shapes, we have:
1. A parallelogram shape.
2. A larger triangle shape and a square shape.


Folding instructions:
With one of your triangle shapes, fold two vertices together as shown and open your sheet once again into a square shape. 
The other triangle shape should be put aside for a further activity.


A discussion question:
On your shape, count the number of congruent triangles. 
Two shapes are congruent when they can cover each other exactly.


Answer:
Looking at the shape we can identify 4 larger triangular shapes and 4 smaller triangular shapes.

Two shapes are congruent when they can cover each other exactly.
.


Folding instructions:
Fold two opposite vertices to meet at the line of symmetry. 
It is important to take notice of the folding done by the pupils.


A discussion question:
In our folded shape, what are the various polygonal shapes that can be seen?


Answer:
In our folded shape, we can find 8 different quadrilateral shapes and two pentagon shapes. 
In the folded shape we can see 2 quadrilateral shapes, 2 square shapes, 2 isosceles trapezoids, 2 pentagon shapes and 4 rightangle trapezoids.
It is not necessary to find all the different polygon shapes only as shown in the animation, as there is also a hexagonal shape and a parallelshaped polygon.


Folding instructions:
Fold together two parallel sides as shown in the animation. 
It is important to take notice of the folding done by the pupils.


A discussion question:
After folding, which polygon shape can be seen now? 
Identifying the different shapes will be done according to the number of sides.
.


Answer:
A quadrilateral shape named a trapezoid. 
The quadrilateral is named an isosceles trapezoid.


Answer:
The polygon shape is a quadrilateral with 4 sides and 4 vertices and is called a trapezoid. 
The quadrilateral is called an isosceles trapezoid.
.


Activity:
Mark in red the nonparallel edges of the trapezoid and also the line of symmetry. 
At this stage, it is important to stress the need of proper markings which will aid the pupils in a later folding. Take notice that the pupils have done all of the necessary markings.


Folding instructions:
Fold the 2 nonparallel sides marked in red to the line of symmetry, as shown in the animation. 
Pay attention to the correct folding of the pupils. Before folding, it is important that the pupils will point out which sides are to be folded and which is the line of symmetry.


Folding instructions:
Fold inwards the marked vertices. 
The size of the fold is not important and pupils can decide in which direction they fold the marked vertices.


Folding instructions:
Turn your shape over to the other side.


A discussion question:
Which different polygon shapes can be seen in your folded shape?
Explain. 
At this stage there will be a variety of answers depending on the size of the folds done by each pupil.


Answer:
We can see a polygon shape of 6sides named a hexagon and 2 quadrilaterals. 
Due to different folds of the pupils, they may notice different polygon shapes.


A suggestion:
Color the face of the rabbit shape.


Final activity:
Take the other sheet that you put aside and make 3 folds of your choice, but do not open the sheet. Then, press to tighten the folds and open your sheet. 
The pupils can mark each fold with a clear line or color to highlight each shape as seen on the opened sheet. They should write the matching name to each polygon on their sheet.
This can also be a homework activity.


Final activity:
Color each polygon in a different color and identify each shape.

In 1st grade, it is suggested to have a class discussion about the various polygons that have been colored.
In 2nd grade it is suggested to discuss the various names of these polygons.


At the end of the lesson press on the X symbol.

The developers will appreciate your feedback.
 Lesson Aims
The pupils will fold and identify shapes according to their properties.
The pupils will use paper folding in order to make geometric shapes and investigate their properties.
 Name of Model
A rabbit finger puppet
 The lesson structure
measuring tool for comparison of lengths ,Polygon activity 3 decomposition and composition 1/2 , Polygon activity 3 decomposition and composition 2/2, Quadrilaterals B: Square & Rectangle – same and different, Quadrilaterals B: Line of reflective symmetry 1/2 Line of reflective symmetry 2/2, Lines of symmetry in quadrilaterals, Perpendicular line and perpendicular side of poligon, Perpendicular line
 Lesson content
In this lesson the pupils investigate polygons that are formed during the folding process. There is a surprise at the end of the lesson. The pupils learn new concepts and refresh their previous learning.
 Prior knowledge
If during the folding process there are cases of inexact folding by some of the pupils, then these cases will be used to identify differences between the polygons and their properties. The pupils will also learn the concept of polygon sides and vertices.
 Materials
 Origami sheets 15 cm x 15 cm, 2 sheets per pupil