Tag: shapes

Pentagon to Quadrilateral Puzzle

Puzzles involving cutting shapes and forming them into different shapes helps reinforce the idea that area do not necessarily change with change in shape. It is also a good activity for developing visualisation skill and spatial ability. The puzzle below is from one of the leaflets at the booth of Japan Society of Mathematical Education last ICME…

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A triangle is a fish

Why is it that students find it easier to calculate the area of triangle ABC but will have difficulty calculating the area of triangle DEF? Middle school students even believe that it’s impossible to find the area of DEF because the triangle has no base and height! That knowing the invariant properties that makes a…

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