### Pebbles

Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?

### Great Squares

Investigate how this pattern of squares continues. You could measure lengths, areas and angles.

### Square Areas

Can you work out the area of the inner square and give an explanation of how you did it?

# Growing Rectangles

##### Stage: 3 Challenge Level:

Imagine a rectangle with an area of $20$cm$^2$
What could its length and width be? List at least five different combinations.

If you enlarge each of your rectangles by a scale factor of 2, what would their new dimensions be?

What would their areas be?

What do you notice?

What happens when you enlarge rectangles with different areas by a scale factor of 2?

What if you enlarge them by a scale factor of 3? Or 4? Or 5 ...? Or $k$?

What if $k$ is a fraction?

Explain and justify any conclusions you come to.

Do your conclusions apply to plane shapes other than rectangles?

Now explore what happens to the surface area and volume of different cuboids when they are enlarged by different scale factors.