![Where are they?](/sites/default/files/styles/medium/public/thumbnails/content-01-05-penta5-icon.jpg?itok=vQKj3HKa)
2D shapes and their properties
![Where are they?](/sites/default/files/styles/medium/public/thumbnails/content-01-05-penta5-icon.jpg?itok=vQKj3HKa)
![Same Shapes](/sites/default/files/styles/medium/public/thumbnails/content-00-03-penta2-icon.jpg?itok=sRuRmtFM)
problem
Same Shapes
How can these shapes be cut in half to make two shapes the same
shape and size? Can you find more than one way to do it?
![Count the Trapeziums](/sites/default/files/styles/medium/public/thumbnails/content-99-04-penta4-icon.gif?itok=N2kCjNaX)
![Squaring the Circle and Circling the square](/sites/default/files/styles/medium/public/thumbnails/content-03-03-six6-icon.gif?itok=zlvrmRmL)
problem
Squaring the Circle and Circling the square
If you continue the pattern, can you predict what each of the following areas will be? Try to explain your prediction.
![Playground Snapshot](/sites/default/files/styles/medium/public/thumbnails/content-03-02-six3-icon.gif?itok=Lwdp6cp2)
problem
Playground Snapshot
The image in this problem is part of a piece of equipment found in the playground of a school. How would you describe it to someone over the phone?
![Squaring the circle](/sites/default/files/styles/medium/public/thumbnails/content-03-01-six6-icon.gif?itok=SbFOlPe1)
problem
Squaring the circle
Bluey-green, white and transparent squares with a few odd bits of
shapes around the perimeter. But, how many squares are there of
each type in the complete circle? Study the picture and make an
estimate.
![Semi-Square](/sites/default/files/styles/medium/public/thumbnails/content-03-01-six3-icon.gif?itok=P6FCl_V6)
problem
Semi-Square
What is the ratio of the area of a square inscribed in a semicircle to the area of the square inscribed in the entire circle?
![Crescents and triangles](/sites/default/files/styles/medium/public/thumbnails/content-02-11-six4-icon.gif?itok=4_v4rZxS)
problem
Crescents and triangles
Can you find a relationship between the area of the crescents and the area of the triangle?
![Approximating Pi](/sites/default/files/styles/medium/public/thumbnails/content-02-05-six2-icon.jpg?itok=r817IXMl)
problem
Approximating Pi
By inscribing a circle in a square and then a square in a circle
find an approximation to pi. By using a hexagon, can you improve on
the approximation?
![Blue and White](/sites/default/files/styles/medium/public/thumbnails/content-01-11-six6-icon.gif?itok=G2gZ8gCq)
problem
Blue and White
Identical squares of side one unit contain some circles shaded blue. In which of the four examples is the shaded area greatest?