It's easy to work out the areas of most squares that we meet, but what if they were tilted?
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.
What are the areas of these triangles? What do you notice? Can you generalise to other "families" of triangles?
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
An investigation that gives you the opportunity to make and justify predictions.
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?
What can you say about these shapes? This problem challenges you to create shapes with different areas and perimeters.
How have "Warmsnug" arrived at the prices shown on their windows? Which window has been given an incorrect price?
How many centimetres of rope will I need to make another mat just like the one I have here?
Look at the mathematics that is all around us - this circular window is a wonderful example.
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. . . .
Cut differently-sized square corners from a square piece of paper to make boxes without lids. Do they all have the same volume?
How many ways can you find of tiling the square patio, using square tiles of different sizes?
This rectangle is cut into five pieces which fit exactly into a triangular outline and also into a square outline where the triangle, the rectangle and the square have equal areas.
A thoughtful shepherd used bales of straw to protect the area around his lambs. Explore how you can arrange the bales.
Identical squares of side one unit contain some circles shaded blue. In which of the four examples is the shaded area greatest?
What happens to the area of a square if you double the length of the sides? Try the same thing with rectangles, diamonds and other shapes. How do the four smaller ones fit into the larger one?
Can you draw a square in which the perimeter is numerically equal to the area?
Can you maximise the area available to a grazing goat?
What is the smallest number of tiles needed to tile this patio? Can you investigate patios of different sizes?
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 help the children find the two triangles which have the lengths of two sides numerically equal to their areas?
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?
If you have only 40 metres of fencing available, what is the maximum area of land you can fence off?
Can you find rectangles where the value of the area is the same as the value of the perimeter?
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?
These rectangles have been torn. How many squares did each one have inside it before it was ripped?
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. . . .
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?
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?
What is the largest 'ribbon square' you can make? And the smallest? How many different squares can you make altogether?
These practical challenges are all about making a 'tray' and covering it with paper.
A follow-up activity to Tiles in the Garden.
I'm thinking of a rectangle with an area of 24. What could its perimeter be?
Explore one of these five pictures.
This practical challenge invites you to investigate the different squares you can make on a square geoboard or pegboard.
I cut this square into two different shapes. What can you say about the relationship between them?
This article for teachers gives some food for thought when teaching ideas about 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 this area?
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.
Use the information on these cards to draw the shape that is being described.
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.
A simple visual exploration into halving and doubling.
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?
Grandpa was measuring a rug using yards, feet and inches. Can you help William to work out its area?
What do these two triangles have in common? How are they related?
Explore this interactivity and see if you can work out what it does. Could you use it to estimate the area of a shape?
Investigate the area of 'slices' cut off this cube of cheese. What would happen if you had different-sized block of cheese to start with?
How many tiles do we need to tile these patios?
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?