The maths quiz that’s got social media stumped
A TRICKY maths problem is stumping social media.
Sharing the conundrum online, mathematician Ed Southall, from the University of Huddersfield, shared a picture of a pink triangle inside a square, along with the question: "What fraction is shaded?"
Twitter users were quick to jump on the puzzle and many shared their attempts at solving the question - while others admitted that their minds had been boggled by the maths riddle.
Thankfully, education charity CEO David Weston has managed to offer a simple reasoning behind the correct answer - which is a third.
The key to getting the correct answer is working out that the height of the triangle is two thirds that of the square's height.
David explained: "Pink triangle and little triangle have all the same angles: they're 'similar'.
"Base of pink is twice base of little [triangle]. So height of pink is also twice height of little.
"So height of pink is two-thirds of whole square."
The final stage of solving the problem involves using the formula for working out the area of a triangle - half x base x height.
Simplest answer I can think of:— David Weston (@informed_edu) April 24, 2018
- Pink triangle and little triangle have all the same angles: they're 'similar'
- Base of pink is twice base of little
- So height of pink is also twice height of little
- So height of pink is 2/3 of whole square
- So area = half x 1 x 2/3 = 1/3 https://t.co/7Hxz3R4VtH
As the height is two-thirds of the square, you can take the base to be equal to one when using the formula.
So, as David explains, the area is half x one x two-thirds.
This means the area of the triangle is a third of the area of the square.
Did you get it?