What fractions of the largest circle are the two shaded regions?
Identical squares of side one unit contain some circles shaded blue. In which of the four examples is the shaded area greatest?
An investigation that gives you the opportunity to make and justify
At the corner of the cube circular arcs are drawn and the area enclosed shaded. What fraction of the surface area of the cube is shaded? Try working out the answer without recourse to pencil and. . . .
An activity for high-attaining learners which involves making a new cylinder from a cardboard tube.
Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?
What is the largest 'ribbon square' you can make? And the smallest? How many different squares can you make altogether?
These rectangles have been torn. How many squares did each one have
inside it before it was ripped?
How many ways can you find of tiling the square patio, using square
tiles of different sizes?
Nine squares with side lengths 1, 4, 7, 8, 9, 10, 14, 15, and 18 cm can be fitted together to form a rectangle. What are the dimensions of the rectangle?
Points P, Q, R and S each divide the sides AB, BC, CD and DA respectively in the ratio of 2 : 1. Join the points. What is the area of the parallelogram PQRS in relation to the original rectangle?
What is the smallest number of tiles needed to tile this patio? Can
you investigate patios of different sizes?
Can you help the children find the two triangles which have the
lengths of two sides numerically equal to their areas?
What can you say about these shapes? This problem challenges you to create shapes with different areas and perimeters.
A hallway floor is tiled and each tile is one foot square. Given
that the number of tiles around the perimeter is EXACTLY half the
total number of tiles, find the possible dimensions of the hallway.
How many centimetres of rope will I need to make another mat just
like the one I have here?
This article, written for teachers, discusses the merits of different kinds of resources: those which involve exploration and those which centre on calculation.
A tower of squares is built inside a right angled isosceles
triangle. The largest square stands on the hypotenuse. What
fraction of the area of the triangle is covered by the series of
If I use 12 green tiles to represent my lawn, how many different
ways could I arrange them? How many border tiles would I need each
I'm thinking of a rectangle with an area of 24. What could its perimeter be?
A follow-up activity to Tiles in the Garden.
How many tiles do we need to tile these patios?
Polygons drawn on square dotty paper have dots on their perimeter (p) and often internal (i) ones as well. Find a relationship between p, i and the area of the polygons.
Can you rank these sets of quantities in order, from smallest to largest? Can you provide convincing evidence for your rankings?
Can you maximise the area available to a grazing goat?
What happens to the area and volume of 2D and 3D shapes when you
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
A task which depends on members of the group noticing the needs of
others and responding.
Imagine different shaped vessels being filled. Can you work out what the graphs of the water level should look like?
Explore this interactivity and see if you can work out what it
does. Could you use it to estimate the area of a shape?
Look at the mathematics that is all around us - this circular
window is a wonderful example.
How can you change the area of a shape but keep its perimeter the same? How can you change the perimeter but keep the area the same?
Draw some isosceles triangles with an area of $9$cm$^2$ and a vertex at (20,20). If all the vertices must have whole number coordinates, how many is it possible to draw?
Can you draw a square in which the perimeter is numerically equal
to the area?
What shape has Harry drawn on this clock face? Can you find its
area? What is the largest number of square tiles that could cover
Have a good look at these images. Can you describe what is happening? There are plenty more images like this on NRICH's Exploring Squares CD.
It's easy to work out the areas of most squares that we meet, but
what if they were tilted?
If you have only 40 metres of fencing available, what is the maximum area of land you can fence off?
Explore one of these five pictures.
In this game for two players, you throw two dice and find the product. How many shapes can you draw on the grid which have that area or perimeter?
Can you work out the area of the inner square and give an
explanation of how you did it?
These practical challenges are all about making a 'tray' and covering it with paper.
It is possible to dissect any square into smaller squares. What is
the minimum number of squares a 13 by 13 square can be dissected
Which is a better fit, a square peg in a round hole or a round peg
in a square hole?
Semicircles are drawn on the sides of a rectangle ABCD. A circle passing through points ABCD carves out four crescent-shaped regions. Prove that the sum of the areas of the four crescents is equal to. . . .
You have a 12 by 9 foot carpet with an 8 by 1 foot hole exactly in
the middle. Cut the carpet into two pieces to make a 10 by 10 foot
Derive a formula for finding the area of any kite.
Choose a box and work out the smallest rectangle of paper needed to
wrap it so that it is completely covered.
A thoughtful shepherd used bales of straw to protect the area
around his lambs. Explore how you can arrange the bales.
Investigate all the different squares you can make on this 5 by 5 grid by making your starting side go from the bottom left hand point. Can you find out the areas of all these squares?