There are lots of answers to this, depending on what questions you choose to ask. Here is what a teacher from  Tudor Grange Academy Solihull wrote:-  

Attached is my copy of as many answers to the Tri's task as possible. I used it with a year 8 class to get them to practice measuring angles, and to get them doing more problem solving and thinking laterally as part of my angles scheme of work. I got them to compete to see who could find the most different solutions, then got them thinking about whether the triangles were scalene, isosceles, right-angled, thinking about why none of them were equilateral, which of them were right angled, and discussing why using a protractor to measure the angles can be much less accurate than using mathematical methods to calculate the exact angles.

   

Thanks a lot for those they're great and show some good signs of creativity.


Have a go yourself, and if you discover anything interesting then email primary.nrich@maths.org. Please don't worry that your solution is not "complete" - we'd like to hear about anything you have tried. Teachers - you might like to send in a summary of your children's work.