This question isn’t your typical busy messy rider. Instead, you’re invited to make it messy yourself, by filling in your own constructions as you see fit! My approach to the question is very Euclidean geometryish, drawing on a couple of our favourite theorems — tan-chord, angle at centre — and also some of the good old basics, like the properties of isosceles triangles. It uses a liiiittle bit of trig right at the end, and then from there it’s fascinating to look at the solutions in the memos, as those went in a very-very-much-trig direction! At the end of the day, all roads lead to Rome and no one solution is more correct than the other. I hope you have lots of fun diving into this beautiful creative question.