Perpendicular Line


THE ORIGAMETRIA
PROGRAM
.


Each pupil chooses a sheet of origami paper.Two colored markers are needed and also the measuring tool

This lesson should be given after the lesson on intersecting and perpendicular lines.


Folding instructions: Fold opposite sides of your sheet.


Folding instructions: Fold opposite sides of the sheet as shown.

The folding should be done only by the pupils.


Instructions: Use your measuring tool and markers to mark the intersecting lines.

Use the measuring tool as a ruler.


A discussion question: Which angles can be identified at the point of intersection? How can you check this?

Use the measuring tool for checking the angles.


Answer: At the point of intersection of the two colored lines there are right angles.


A discussion question: Which name can be given to the two intersecting lines? Explain.

A class discussion should take place before showing the answer.


Answer: The 2 lines are perpendicular lines.

The 2 lines are also lines of symmetry for the square.


Folding instructions: Fold two adjacent vertices to form 2 triangles as shown.

Check that the pupils have folded the correct triangles.


Folding instructions: Turn over your shape.


Folding instructions: Fold one side of the shape as shown.


Folding instructions: Turn over your shape.


Folding instructions: Fold opposite sides as shown.


Folding instructions: Fold your shape as shown and then open the shape.

Show this fold clearly to the pupils.


Folding instructions: With the shape placed as shown press down on the triangle as in the animation.

As this fold is complex check that it has been done correctly. The teacher should demonstrate this several times .


A discussion question: In the animation we can see 2 segments of lines that are colored. Are these segments perpendicular to each other?

Use the measuring tool for checking.


Answer: The angle measured is a right angle and the two segments are perpendicular to each other.


A discussion question: Are the 2 colored segments in this animation perpendicular?

Before showing the answer a discussion should take part with the pupils.


Answer: The angle between the 2 segments is not a right angle and the segments are not perpendicular to each other.


Folding instructions: Fold the side of the triangle as shown in order to form two triangles.

זAs this fold is complex check that it has been done correctly. The teacher should demonstrate this several times .


Folding instructions: Fold one triangle as shown.

As this fold is complex check that it has been done correctly. The teacher should demonstrate this several times .


Folding instructions: Close the shape on the dotted line as shown.

Close like a book.


Folding instructions: Hold the tail of your fish shape and it will begin swimming!


A discussion question: Which pair of lines are perpendicular? A or B?


A discussion question: Is it possible to draw a line which is perpendicular to the red line? How will you know?

Using the measuring tool each pupil should draw a line of his own in his workbook and the draw a perpendicular line to the first line.


Class activity: Find pairs of perpendicular lines in your classroom. How can you check ?
 Lesson Aims
Pupils will recognise perpendicular lines and draw perpendicular lines.
 Name of Model
The swimming fish.
 The Lesson Structure
The measuring tool,Composition and Decomposition of Shapes, Polygons 3,Perpendicular lines and sides of polygons.
 Lesson Content
In this lesson the pupils will investigate perpendicular and intersecting lines. At the conclusion of this lesson the final model will be a surprise while learning new concepts and revising previously learnt geometrical concepts.
 Prior knowledge
Angles,right angle,sides of a polygon.
 Materials
Two sheets of origami paper 15×15 cm,and two colored markers.