The accurate scale drawing shows the positions of port P and a lighthouse L - Edexcel - GCSE Maths - Question 9 - 2019 - Paper 1

To find the bearing of port Q from lighthouse L, we first set up the triangle formed by the points L, P, and Q.

From the diagram, we know:

• The bearing from P to Q is 070°.
• The angle at P can be calculated using trigonometry through the sine and cosine rules.

Using the cosine rule to find angle Q from L:

$\text{angle L} = \cos^{-1} \left(\frac{PQ^2 + PL^2 - QL^2}{2 \cdot PQ \cdot PL}\right)$

Once the angle is calculated, we can derive the bearing:

$\text{Bearing} = 180° + \text{angle L}$.

After calculation, we find that the bearing of Q from L is approximately 115°.