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Arclets Explained
This article gives an wonderful insight into students working on the Arclets problem that first appeared in the Sept 2002 edition of the NRICH website.
2D shapes and their properties
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articlePi, a Very Special Number
Read all about the number pi and the mathematicians who have tried to find out its value as accurately as possible. -
articleCircles, Circles Everywhere
This article for pupils gives some examples of how circles have featured in people's lives for centuries. -
articleWhat's Inside/outside/under the Box?
This article describes investigations that offer opportunities for children to think differently, and pose their own questions, about shapes. -
pageLafayette
What mathematical words can be used to describe this floor covering? How many different shapes can you see inside this photograph? -
pageWatch Those Wheels
Have you ever noticed the patterns in car wheel trims? These questions will make you look at car wheels in a different way! -
articleLet's Get Flexible With Geometry
In this article for primary teachers, Ems explores ways to develop mathematical flexibility through geometry. -
problemArea I'n It
Age16 to 18Challenge level
Triangle ABC has altitudes h1, h2 and h3. The radius of the inscribed circle is r, while the radii of the escribed circles are r1, r2 and r3 respectively. Prove: 1/r = 1/h1 + 1/h2 + 1/h3 = 1/r1 + 1/r2 + 1/r3 . -
problemLawnmower
Age14 to 16Challenge level
A kite shaped lawn consists of an equilateral triangle ABC of side 130 feet and an isosceles triangle BCD in which BD and CD are of length 169 feet. A gardener has a motor mower which cuts strips of grass exactly one foot wide and wishes to cut the entire lawn in parallel strips. What is the minimum number of strips the gardener must mow? -
problemFitting In
Age14 to 16Challenge level
The largest square which fits into a circle is ABCD and EFGH is a square with G and H on the line CD and E and F on the circumference of the circle. Show that AB = 5EF. Similarly the largest equilateral triangle which fits into a circle is LMN and PQR is an equilateral triangle with P and Q on the line LM and R on the circumference of the circle. Show that LM = 3PQ