### 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?

# Semi-circles

##### Stage: 3 Challenge Level:

 Semi-circles are drawn on $AB$, $AC$, $BD$ and $CD$ where $AB = BC = CD$ Show that the large circle is divided into $3$ portions of equal area.