Scroll down to see the complete collection, or explore our subcollections on Perimeter and Area in two dimensions, and Surface Area and Volume in three dimensions.

Perimeter and area

Surface area and volume


F'arc'tion

Arclets

Circle in a semicircle

Pencil turning

Annulus area
Given three concentric circles, shade in the annulus formed by the smaller two. What percentage of the larger circle is now shaded?

Maximised area



Roll on
How many times does the inside disc have to roll around the inside of the ring to return to its initial position?

Running race
If three runners run at the same constant speed around the race tracks, in which order do they finish?



Square ratio

Rolling inside
A circle of radius 1 rolls without slipping round the inside of a square of side length 4. Find an expression for the number of revolutions the circle makes.

Rectangle cutting

Crazy shading

Circled corners

Wood pile perimeter
Three touching circles have an interesting area between them...


Tadpoles

Penny farthing

In or out?
Four arcs are drawn in a circle to create a shaded area. What fraction of the area of the circle is shaded?

Four leaf clover

Cut-up square
In the diagram, two lines have been drawn in a square. What is the ratio of the areas marked?

Emptied cube
What are the volume and surface area of this 'Cubo Vazado' or 'Emptied Cube'?

Square flower

Trisected triangle
Four tiles are given. For which of them can three be placed together to form an equilateral triangle?

Clown hats
Charlie is making clown hats from a piece of cardboard. What is the maximum number he can make?


Semicircular design
The diagram to the right shows a logo made from semi-circular arcs. What fraction of the logo is shaded?

Four parts

Semicircle distance

Square in a circle in a square

Sinking feeling




Cones and spheres

Ratio cut


Loo roll emergency


Similar cylinders



Immersion
Various solids are lowered into a beaker of water. How does the water level rise in each case?

Funnel
A plastic funnel is used to pour liquids through narrow apertures. What shape funnel would use the least amount of plastic to manufacture for any specific volume ?

Fill me up too
In Fill Me Up we invited you to sketch graphs as vessels are filled with water. Can you work out the equations of the graphs?

Gutter
Manufacturers need to minimise the amount of material used to make their product. What is the best cross-section for a gutter?

Curvy areas
Have a go at creating these images based on circles. What do you notice about the areas of the different sections?

Track design
Where should runners start the 200m race so that they have all run the same distance by the finish?

Triangles and petals
An equilateral triangle rotates around regular polygons and produces an outline like a flower. What are the perimeters of the different flowers?

Salinon
This shape comprises four semi-circles. What is the relationship between the area of the shaded region and the area of the circle on AB as diameter?