Answer:
Step-by-step explanation:
The scenario is represented in the attached photo. Triangle ABC is formed. AB represents her distance from her base camp. We would determine BC by applying the law of Cosines which is expressed as
a² = b² + c² - 2abCosA
Where a,b and c are the length of each side of the triangle and B is the angle corresponding to b. It becomes
AB² = AC² + BC² - 2(AC × BC)CosC
AB² = 42² + 28² - 2(42 × 28)Cos58
AB² = 1764 + 784 - 2(1176Cos58)
AB² = 2548 - 1246.37 = 1301.63
AB = √1301.63
AB = 36.08 km
To find the bearing, we would determine angle B by applying sine rule
AB/SinC = AC/SinB
36.08/Sin58 = 42/SinB
Cross multiplying, it becomes
36.08SinB = 42Sin58
SinB = 42Sin58/36.08 = 0.987
B = Sin^-1(0.987)
B = 81°
Therefore, her bearing from the base camp is
360 - 81 = 279°
