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"Hard" sine and cosine rule questions:
13B
$$\begin{align}
AX = \sqrt{ AB^{2}+ XB^{2} - 2 \times AB \times XB \times \cos(20) } \\
AB = \sqrt{ AX^{2} + XB^{2} - 2 \times AX \times XB \times \cos(40) } \\
XB = \sqrt{ AX^{2} + AB^{2} - 2 \times AX \times AB \times \cos(120) }
\end{align}
$$
Classpad is struggling to solve this. TBF the better method is to use sine rule but
