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.
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?
An investigation that gives you the opportunity to make and justify
Identical squares of side one unit contain some circles shaded blue. In which of the four examples is the shaded area greatest?
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?
Can you draw a square in which the perimeter is numerically equal
to the area?
Make an eight by eight square, the layout is the same as a
chessboard. You can print out and use the square below. What is the
area of the square? Divide the square in the way shown by the red
dashed. . . .
How many ways can you find of tiling the square patio, using square
tiles of different sizes?
A red square and a blue square overlap so that the corner of the red square rests on the centre of the blue square. Show that, whatever the orientation of the red square, it covers a quarter of the. . . .
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.
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
It's easy to work out the areas of most squares that we meet, but
what if they were tilted?
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?
My local DIY shop calculates the price of its windows according to the area of glass and the length of frame used. Can you work out how they arrived at these prices?
These practical challenges are all about making a 'tray' and covering it with paper.
What is the largest 'ribbon square' you can make? And the smallest? How many different squares can you make altogether?
I'm thinking of a rectangle with an area of 24. What could its perimeter be?
How many tiles do we need to tile these patios?
Can you find rectangles where the value of the area is the same as the value of the perimeter?
If you have only 40 metres of fencing available, what is the maximum area of land you can fence off?
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
Can you help the children find the two triangles which have the
lengths of two sides numerically equal to their areas?
How many centimetres of rope will I need to make another mat just
like the one I have here?
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. . . .
This practical challenge invites you to investigate the different
squares you can make on a square geoboard or pegboard.
What are the areas of these triangles? What do you notice? Can you generalise to other "families" of triangles?
Cut differently-sized square corners from a square piece of paper
to make boxes without lids. Do they all have the same volume?
What is the smallest number of tiles needed to tile this patio? Can
you investigate patios of different sizes?
These rectangles have been torn. How many squares did each one have
inside it before it was ripped?
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?
How have "Warmsnug" arrived at the prices shown on their windows? Which window has been given an incorrect price?
Explore this interactivity and see if you can work out what it
does. Could you use it to estimate the area of a shape?
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?
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
Is it possible to remove ten unit cubes from a 3 by 3 by 3 cube made from 27 unit cubes so that the surface area of the remaining solid is the same as the surface area of the original 3 by 3 by 3. . . .
Can you maximise the area available to a grazing goat?
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.
Can you work out the area of the inner square and give an
explanation of how you did it?
What is the largest number of circles we can fit into the frame
without them overlapping? How do you know? What will happen if you
try the other shapes?
Can you rank these sets of quantities in order, from smallest to largest? Can you provide convincing evidence for your rankings?
A follow-up activity to Tiles in the Garden.
Investigate the area of 'slices' cut off this cube of cheese. What
would happen if you had different-sized block of cheese to start
Are these statements always true, sometimes true or never true?
Explore one of these five pictures.
These pictures were made by starting with a square, finding the half-way point on each side and joining those points up. You could investigate your own starting shape.
I cut this square into two different shapes. What can you say about
the relationship between them?
Imagine different shaped vessels being filled. Can you work out what the graphs of the water level should look like?
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