Dominique BODIN

Thanks for this problem.

The best problem I've ever come accross with the shear transformation. Thanks a lot.

And to make easier to see the area of the squares in the two cases, Ss may use these two cutting of the squares.

Square peg in a round hole is a better fit than a square peg in a round hole. Thanks for this clever problem.

22/3 area units. Thanks for this nice problem.

The total blue area is equal to 180cm².
Show how to find out the perimeter of this blue triangle.

The idea here was to take 6 units for the two remainders beacause 6 is a multiple of 2 (2 thirds remaining) and 3 (3 quarters remaining). I wonder how to guide Ss to this kind of thinking. Thanks for the problem.

Moving one vertex of one the blue triangles on a parallel line to one of its other side doesn't change its area.So if we slice the blue area in two triangles, the total blue area is equal to 2cm×5cm=10cm² since each triangle's area is equal to one half of the rectangle area.Thanks for this fun task.

Moving one vertex of the blue triangle on a parallel line to one of its side doesn't change its area. So both rectangles have the same area which is twice as much as the blue one. Thanks for this nice task.
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