CLASSIFICATION OF PYRAMIDS


A discussion question: Which of the solids in the picture is a polyhedron? How is a polyhedron defined? Explain.

Polyhedra are threedimensional objects made of polygons.


Answer: Polyhedra are threedimensional objects made of polygons. Only A solids are polyhedra if we can see all the polygon faces of the solids.

Aonly if we can see all the faces of the solids.


Each pupil chooses 5 sheets of origami paper.


Folding instructions: Fold opposite parallel sides of all sheets.The folds should be exact.

All effort must be made to make these fold exactly. The process of folding should be done slowly.


Folding instructions: Mark 2 opposite vertices as shown on all of the folded sheets.


Folding instructions: Put all of the folded sheets onto each other and check that they are all marked in the same way.


Folding instructions: Fold opposite vertices as shown on all of the rectangular shapes.


Folding instructions: Put all of the folded sheets onto each other and check that they are all marked in the same way and direction.


Folding instructions: Fold a triangle as shown and open the fold.


Folding instructions: Turn over the shape.


Folding instructions:Fold a triangle as shown and open the fold.


Folding instructions: Place the folded and opened triangle inside as shown.


Folding instructions: Fold the marked triangle into the pocket.


Folding instructions:Fold the marked triangle into the pocket as shown.


Folding instructions:Fold the marked triangle into the pocket as shown.


A discussion question: What type of pyramid has been made after joining the three shapes?


Answer: We have made the envelope of a triangular pyramid with three congruent triangles meeting at a common vertex.


A discussion question: Look at the envelope. What shape should be added in order to complete the pyramid?


Answer: The shape to be added is a triangle and it is named the base of this pyramid.

All sides of the pyramid can be named as a base of the pyramid.


A discussion question: What is the number of vertices of the triangular pyramid? Explain.

It should be pointed out that the pupils have folded the envelope of a triangular pyramid and without the addition of another side it is not a pyramid.


Answer: The triangular pyramid has 4 vertices.


A discussion question: How many edges are there on a triangular pyramid? Explain.

The sides of polyhedra are called edges.
Faces, Edges, and Vertices identify polyhedra.


Answer: There are 6 edges.


A discussion question: How many faces are there on a triangular pyramid? Explain.


Answer: A triangular pyramid has 4 faces.

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A group activity: Using additional folded shapes make the envelopes of other pyramids.


We can make the envelope of a pyramid with 4 folded shapes.


This envelope is the envelope of a square pyramid.The base of a square pyramid is a square.

Using the same folding instructions it is possible to make pentagonal and hexagonal pyramid envelopes.


An envelope of a pentagonal pyramid has been made.


Adding the pentagonal base to the envelope we have a pentagonal pyramid named after the base.


A group activity: Make a list of the number of all the faces,edges and vertices of a pentagonal pyramid.

A worksheet is attached.


A discussion question: Mayans built pyramids. Is the picture shown a pyramid? Explain.


Answer: The shape in Mexico shown in the picture is in the shape of a pyramid but it is not a geometrical pyramid.


A discussion question: Which of the two pictures show a geometrical pyramid?


Answer: Only the B picture represents a true geometrical pyramid because all the face have a common vertex.

The B picture shows a square pyramid.


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 Lesson Aims
 Investigating pyramids.
 Investigating the faces,edges and vertices of pyramids.
 Folding envelopes of pyramids.
 Name of Model
Envelopes of triangular,square and pentagonal pyramids.
 Lesson Structure
According to curriculum.
 Lesson Content
Folding and assembling envelopes of triangular,square and pentagonal pyramids.Listing faces,edges and vertices of pyramids.
 Prior Knowledge
Quadrilaterals and polygons.
 Materials
5 origami sheets 15cm x15 cm.
Worksheet on the subject of pyramids