4.4 Geometry

First of all, test your memory. Explain the meaning of “symmetrical” to your friend.

1. Use magazines to find pictures of shapes / figures that are symmetrical.

• Paste them on to the sheet of paper given to you by your teacher.
• Indicate the axis of symmetry with a coloured chalk. (Use your ruler!)

2. Do the following:

• Neatly copy the shapes that you used for the table in Activity 1.7 onto a sheet of paper. (Ask your teacher for some paper.) You can draw them as large as you like.
• Indicate the axes of symmetry neatly.

Activity 6:

To examine and compare 3d objects [lo 3.3.1]

To recognise 3d objects [lo 3.1.1]

So far we have worked with 2-dimensional shapes. Let’s now take a good look at 3-dimensional figures.

1. Have a class discussion. What is the difference between 2-dimensional and 3-dimensional figures?

2. How would you like to be an architect and a builder? Now you and your friend have the opportunity to build the school of your dreams! You need the following:

• a large sheet of cardboard
• glue and a pair of scissors
• matchboxes, etc. (Use your own, clever ideas!)

This school must have classrooms and there must be a round swimming pool. Naturally you will also want a computer centre and a school hall. The changing rooms and the rugby field must be close together.

First study the following useful information before you start:

The following information might be useful:

A structure like a matchbox is called a RECTANGULAR PRISM , because the faces are all rectangles.

A CUBE is a special type of rectangular prism, because the FACES of a cube are all squares.

3. After your model has been completed, you must complete the table below. Look at the figures you have made. If, for instance, the hall is a rectangular prism, it must be written in the applicable column.

Activity 7:

To make patterns from geometric shapes and to describe them in terms of tessellations [lo 3.5.1]

Tessellations

Think about how tiles are laid on a wall or the floor of a bathroom. The tiles fit exactly against one another. The spaces you can see are only there for the cement or glue so that the tiles can stick properly and will not fall off.

The tiles usually look like this when they are laid:

We say the tiles TESSELLATE because they fit into one another EXACTLY without spaces between them.

1. This afternoon when you are at home, look at the tiles in your bathroom, kitchen or any other room. You could also look at the floor or wall tiles in any shop in your area. Make a drawing of what they look like in the box below:

2. Now look at the drawing of the tiles above. Can you see that the inside tiles are rectangles and the outside tiles are triangles ?

Now make your own patterns by combining

• triangles
• quadrilaterals
• pentagons
• any creative shape

Assessment

Memorandum

ACTIVITY 3

1. 6

2. 5

3. 6

4. 4

ACTIVITY 4

6 ; 7

3 ; 6 ; 10 ; 98 ; 218