ANSWER
[tex](10)sin(40 \degree) = AC[/tex]
EXPLANATION
The given triangle ABC is a right angle triangle.
Side AC of ∆ABC is opposite to the known angle which is
[tex]40 \degree[/tex]
The hypotenuse of the right angle triangle ABC is 10 in.
We use the sine ratio to arrive at the required equation.
Recall that, the sine ratio is given by
[tex] \sin( \theta) = \frac{length \: of \: opposite \: side}{length \: of \: the \: hypotenuse} [/tex]
This implies that,
[tex] \sin(40 \degree) = \frac{AC}{10} [/tex]
We now make AC the subject to obtain,
[tex]AC = (10) \sin(40 \degree) [/tex]
The correct answer is A.
