Question

X = A 21.6 B 12.9 C 9.1

Answer 1

B

Explanation:

Using the sine ratio in the right triangle

sin57° =
`(opposite)/(hypotenuse)` =
`(AC)/(AB)` =
`(12)/(x)` ( multiply both sides by x )

x × sin57° = 12 ( divide both sides by sin57° )

x =
`(12)/(sin57)` ≈ 12.9 ( to 1 dec. place ) → B

Answer 2

B: 12.9

Explanation:

If A B and C are the alternatives, the answer is B: 12.9

The reason is that the hypotenuse can't be smaller than one of its sides, that eliminates alternative C.

And also, the hypotenuse can't be bigger than segments AC + BC, since the side AC is bigger and AC measures 10.8, the hypotenuse would have to measure < 21.6

Any questions, comment.