# Puzzles

## Archive

Show me a random puzzle**Most recent collections**

#### Sunday Afternoon Maths LXVII

Coloured weightsNot Roman numerals

#### Advent calendar 2018

#### Sunday Afternoon Maths LXVI

Cryptic crossnumber #2#### Sunday Afternoon Maths LXV

Cryptic crossnumber #1Breaking Chocolate

Square and cube endings

List of all puzzles

## Tags

polygons perfect numbers triangle numbers number functions christmas proportion parabolas quadratics spheres symmetry doubling sport palindromes 2d shapes planes floors coordinates cryptic clues graphs unit fractions money folding tube maps wordplay balancing fractions pascal's triangle hexagons sums integers probability arrows multiples shapes addition remainders books mean irreducible numbers 3d shapes star numbers clocks dodecagons circles scales squares sum to infinity cryptic crossnumbers division indices volume square numbers numbers routes rugby integration square roots averages ave area multiplication crossnumbers odd numbers surds factors cube numbers menace lines speed rectangles advent chalkdust crossnumber differentiation chocolate colouring dice people maths coins geometry shape algebra factorials angles bases probabilty games sequences partitions means taxicab geometry ellipses digits grids dates regular shapes cards prime numbers time chess trigonometry logic calculus crosswords perimeter triangles complex numbers percentages## Polygraph

Draw a regular polygon. Connect all its vertices to every other vertex. For example, if you picked a pentagon or a hexagon, the result would look as follows:

Colour the regions of your shape so that no two regions which share an edge are the same colour. (Regions which only meet at one point can be the same colour.)

What is the least number of colours which this can be done with?