9514 1404 393
Answer:
78.5 km
Step-by-step explanation:
Measured at the airport, the angle between the two planes is ...
180° -60° -50° = 70°
The law of cosines tells us the distance between the planes is ...
d = √(50² +80² -2·50·80·cos(70°)) ≈ √6163.84 ≈ 78.5 . . . km
The planes are about 78.5 km apart.
9514 1404 393
Answer:
Step-by-step explanation:
The Law of Cosines can be used to find the distance from the red boat to the lighthouse.
b² = l² +r² -2lr·cos(B)
b² = 18² +30² +2·18·30·cos(120°) = 1764
b = √1764 = 42
The distance from the red boat to the lighthouse is 42 miles.
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The angle at the lighthouse can be found using the law of sines.
sin(L)/l = sin(B)/b
L = arcsin(l/b·sin(B)) = arcsin(18/42·sin(120°)) ≈ 21.79°
The angle between the boats measured at the lighthouse is about 22°.
