Riddle solved, 122-year debate ends To solve the puzzle, the trio grouped possible dissections of an equilateral triangle based on how the cuts intersect its edges.

Learn about angles in triangles and quadrilaterals with this BBC Bitesize Maths article. For students between the ages of 11 and 14.

News Weird News Brainteasers You need to be a 'maths wizard' to solve baffling triangle brainteaser Brainteasers have been proven to improve your lateral thinking skills and proponents claim they ...

A tricky brainteaser is challenging participants to put the numbers one to nine between the nine circles provided around a triangle - but can you solve it?

The video says: "If you can solve this brainteaser, you are a math wizard. The rules are simple, place the numbers one to nine in the circles below so that every side adds up to 17.

Learn about angles in triangles and quadrilaterals with this BBC Bitesize Maths article. For students between the ages of 11 and 14.