Regular polygons and circles

There are 118 NRICH Mathematical resources connected to Regular polygons and circles
Olympic rings
problem
Favourite

Olympic rings

Age
5 to 7
Challenge level
filled star filled star empty star

Can you design your own version of the Olympic rings, using interlocking squares instead of circles?

LOGOSquares
problem
Favourite

Logosquares

Age
16 to 18
Challenge level
filled star empty star empty star
Ten squares form regular rings either with adjacent or opposite vertices touching. Calculate the inner and outer radii of the rings that surround the squares.
Hex
problem
Favourite

Hex

Age
11 to 14
Challenge level
filled star empty star empty star
Explain how the thirteen pieces making up the regular hexagon shown in the diagram can be re-assembled to form three smaller regular hexagons congruent to each other.
Approximating Pi
problem
Favourite

Approximating pi

Age
14 to 18
Challenge level
filled star filled star filled star
By inscribing a circle in a square and then a square in a circle find an approximation to pi. By using a hexagon, can you improve on the approximation?
Semi-detached
problem
Favourite

Semi-detached

Age
14 to 16
Challenge level
filled star filled star empty star
A square of area 40 square cms is inscribed in a semicircle. Find the area of the square that could be inscribed in a circle of the same radius.
Overlapping Again
problem
Favourite

Overlapping again

Age
7 to 11
Challenge level
filled star filled star empty star
What shape is the overlap when you slide one of these shapes half way across another? Can you picture it in your head? Use the interactivity to check your visualisation.
So Big
problem
Favourite

So big

Age
16 to 18
Challenge level
filled star filled star empty star
One side of a triangle is divided into segments of length a and b by the inscribed circle, with radius r. Prove that the area is: abr(a+b)/ab-r^2
Orthogonal Circle
problem
Favourite

Orthogonal circle

Age
16 to 18
Challenge level
filled star filled star empty star
Given any three non intersecting circles in the plane find another circle or straight line which cuts all three circles orthogonally.
Partly Circles
problem
Favourite

Partly circles

Age
14 to 16
Challenge level
filled star filled star filled star
What is the same and what is different about these circle questions? What connections can you make?
Bracelets
problem
Favourite

Bracelets

Age
7 to 11
Challenge level
filled star empty star empty star

Investigate the different shaped bracelets you could make from 18 different spherical beads. How do they compare if you use 24 beads?