Answer:
2.0 km
Explanation:
The Law of Cosines can be used to find the third side of a triangle in which two sides and the angle between them are given.
Setup
The law of cosines tells us ...
c² = a² +b² -2ab·cos(C)
Using the given values, we have ...
c² = 4.2² +4.5² -2(4.2)(4.5)cos(26°)
Solution
Simplifying the equation, we get ...
c² = 37.89 -37.8cos(26°) ≈ 3.91559
c ≈ 1.979 . . . . km
The width of the strait is about 2.0 km.