Stage: 3 Challenge Level: 
Imagine you have any number of equilateral triangles all of the same size as well as a large number of 30°, 30°, 120° isosceles triangles with the shorter sides the same length as the equilateral triangles.
Using these triangles how many differently shaped rectangles can you build?
Can you make a square?
The interactivity below may help you with this problem.Click on
the green or yellow triangles to get a copy. Drag the triangle
by its interior to the required position and drag any vertex to
rotate it.
This text is usually replaced by the Flash movie.
Rotations. Compound transformations. Quadrilaterals. Rational and irrational numbers. Translations. Logo. Generalising. Reflections. Practical Activity. Visualising.
Published April 2001.
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email: nrich@damtp.cam.ac.uk
