Navigation buoys around a marina

Navigation buoys around a marina

Secondary 3
9 marks
Original parallel to supplied E Math applications of trigonometry references

Buoys \(M\), \(N\) and \(R\) are on horizontal water.

\(M\) is at a bearing of \(038^\circ\) from \(N\), while \(R\) is at a bearing of \(132^\circ\) from \(M\).

\(MN=72\text{ m}\) and \(MR=55\text{ m}\).

Give non-exact numerical answers correct to \(3\) significant figures.

  1. Find the bearing of \(N\) from \(M\).[1]
  2. Find the area of triangle \(MNR\).[2]
  3. Find \(NR\).[2]
  4. Find \(\angle MRN\).[2]
  5. A patrol launch travels directly from \(N\) to \(R\). Find the shortest distance between the launch and \(M\) during the journey.[2]

Solution:

Solution locked

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Answer:(a) \(218^\circ\) (b) \(1980\text{ m}^2\) (c) \(87.5\text{ m}\) (d) \(55.2^\circ\) (e) \(45.1\text{ m}\)

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