Yesterday we did a project on this geometry problem shared by Catriona Agg:
I also shared the problem on Facebook and a friend from college shared a solution that I’d not seen before (though looking back at Catriona’s twitter thread, it is there . . . . of course!). So, today I decided to take a 2nd day with the problem and have my son look at this new solution.
But I started by having him explain the “power of point” solution I shared with him yesterday just to get warmed up:
Next I set up my friend Raf’s solution to see if my son could solve the problem using this clever idea:
Finally, since the solution with the full inscribed circle depends on a geometry formula relating the area and perimeter of a triangle to the length of the radius of the inscribed circle, I asked my son if he could prove that formula was true. It took him a minute to find the idea, but he was able to construct the proof:
I was happy to be able to share three different solutions to the problem that Catriona shared. It definitely made for a fun little weekend geometry review!