Yesterday Catriona Agg shared a nice geometry problem on Twitter:

In a @MathsHubs meeting today, we were given this to ponder over lunch: how many interesting solutions can you come up with?

Lunch break was just long enough for me to teach Y13, so I gave it to them. I had 3 solutions, they gave me 2 more – one of which is my favourite by far. pic.twitter.com/Wu6XB91b4m

I thought this problem would be a great one for my younger son to work through, so I asked him to give it a try this morning. Here’s how he explained his work:

Usually when I share one of Catriona’s problems I ask him to go through the twitter thread to pick out one of the cool solutions. We took a different approach today as we’d talked about “power of a point” a few weeks ago and I wanted to show him how that idea could be used to solve the problem:

I really like this problem and especially like how different solutions bring in different parts of high school geometry. Thanks (for the 1,000th time!) to Catriona for sharing a great little puzzle 🙂