How on earth do you do this bearing/trigonometry question?

Science & Mathematics by Anonymous 2018-07-01 04:33:24

Social Science

7 answers

Anonymous

143.57 km
Anonymous

80+72cos 28 = 143.6 km
Anonymous

Way to technical
Anonymous

see drawing cos 28º = BF/72 = DE/72 DE = 72 cos 28 = 63.6 AE = AD + DE = 80 + 63.6 = 143.6 km
Anonymous

How far is C east of B? Call that distance X. Sin 62 = X/72 X = 72 sin 62 Work out X, and add it to 80km (the distance B is east of A.) Edit: Mathmom's comment answers your question; bill's diagram clarifies it too.
Anonymous

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Anonymous

80 + 72 * cos(90 - 62) => 80 + 72 * cos(28) => 143.57222668584273982631633794273.... 143.572 km