Stage: 2 Challenge Level: 
Why do this problem?
This
problem, as in Overlaps, focuses
on encouraging children to visualise - in this case to picture an
image in their head. There are also valuable opportunities for them
to apply their knowledge of properties of shape and to use
appropriate vocabulary.
Visualising can be a very useful way of getting into a
problem, as well as helping at other stages of the problem-solving
process. Providing opportunities like this for your class to
practise visualising will help them become familiar with its uses
and to regard it as a legitimate skill to draw upon.
Key questions
What are the two shapes you are thinking about?
Looking at the overlaps where the sides are diagonal, which
shapes could they have come from?
Can you imagine gradually moving one shape across the other
one?
Possible extension
Learners who need more of a challenge could try Quadrilaterals.Possible support
Suggest trying this simpler version of the problem.Compound transformations. Practical Activity. Interactivities. Circles. Quadrilaterals. Games. Equilateral triangles. Visualising. Hexagons. Pentagons.
Published October 2007.
Copyright © 2007. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project, which also includes the Plus and Motivate sites.
email: nrich@damtp.cam.ac.uk