Why do this
There are several different ways of solving this
. It is a good example to bring home the point that, to
be an expert problem solver, and to understand a piece of
mathematics, it is not enough to find an answer. One should ask
oneself "Have I used the best method?". This problem can be solved
using trig formulae and the cosine rule but it can be solved more
straightforwardly using only Pythagoras theorem.
Challenge the class to find different methods of solution.
How do we interpret the two solutions?
Is the diagram correct for both solutions?