Equal lengths

The picture below shows two copies of the same rectangle with red and blue lines. The blue line visits the midpoint of the opposite side. The lengths shown in red and blue are of equal length.
What is the ratio of the sides of the rectangle?

Show answer

1 December

What is area of the largest area rectangle which will fit in a circle of radius 10?

Show answer


Show me a random puzzle
 Most recent collections 

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2020