A piece of string 10cm long is tied to two pins 6cm apart. The string is used to draw an ellipse. The pins are then moved 2cm further apart and a second ellipse is drawn. Which ellipse has the larger area?

Show answer & extension

If you enjoyed this puzzle, check out Sunday Afternoon Maths VI,
puzzles about ellipses, or a random puzzle.


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


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


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