Advent calendar 2019

19 December

The diagram below shows three squares and five circles. The four smaller circles are all the same size, and the red square's vertices are the centres of these circles.
The area of the blue square is 14 units. What is the area of the red square?

Show answer


Show me a random puzzle
 Most recent collections 

Advent calendar 2020

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2021