Mathematician Ed Southall from the University of Huddersfield, UK, posed the devious question on Twitter, asking his followers to work out what fraction of a square was shaded pink.
At first, it looks like there’s no clear answer. But using one of a few methods, it’s possible to work it out.
Some users of course responded with smart-ass comments.
Others were close, but no cigar.
While a few were simply too cool for school.
Fear not, if you haven’t been able to solve it yet. Because a number of people did, although their methods of getting there were vastly different.
One solution as outlined by David Weston, the CEO of charity Teacher Development Trust, was to realize that all the triangles have the same angles.
Assuming the little triangle goes half way along the square, then the base of the pink one is twice the base of the little one, as is its height.
This makes its area half times 1 times 2/3, as the area of a triangle is half base times height, giving an answer – presumably the correct one – of 1/3.
However, that’s not the only way to arrive at this answer. Oh no. Some people had some vastly different methods and, well, they certainly got a bit more elaborate.
Did you arrive at the right answer and, if so, how did you do it? Let us know in the comments below.