3x3 Areas

Which of the following shaded regions has an area different from the other shaded regions?
Age
11 to 14
Challenge level
filled star empty star empty star
Exploring and noticing Working systematically Conjecturing and generalising Visualising and representing Reasoning, convincing and proving
Being curious Being resourceful Being resilient Being collaborative
Which of the following shaded regions has an area different from the other shaded regions?


3x3 Areas

 

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.