Cambridge University’s Underground Mathematics is an outstanding resource for teachers of students age 16-19 and I believe will be an important source of ideas for teaching the new Advanced Level specifications.
I regularly feature favourite resources; here’s a great way to look at circles! The teddy bear! As with all the resources on Underground mathematics much more than just the problem is available; note the printable/ supporting materials for the teddy bear problem. Note also that this problem features in Resources in Action, see this extensive teacher support on using The teddy bear in the classroom. For more on Circles – see the Circles Station.
I can never resist creating a Desmos page!