Question

Answer to 9a is 11.3km

Answer 1

11.3 Km

Explanation:

Consider the right triangle formed by AB and West.

The acute angle WAB = 270° - 250° = 20°

and West is the adjacent side of the right triangle with AB the hypotenuse

Using the cosine ratio in the right triangle, then

cos20° =
`(adjacent)/(hypotenuse)` =
`(adj)/(12)`

Multiply both sides by 12

12 × cos20° = adjacent

11.2763.. = adjacent, that is

B is 11.3 Km west of A