Answer
The correct answer is A.
Explanation
The given triangle is a right triangle.
The length of the hypotenuse is [tex]2.5[/tex] units.
The given angle is [tex]39\degree[/tex].
The unknown side [tex]x[/tex] is adjacent to the given angle.
We can therefore use the cosine function to find [tex]x[/tex].
Recall the mnemonics CAH.
This means that;
[tex]\cos\theta=\frac{Adjacent}{Hypotenuse}[/tex]
This implies that,
[tex]\cos39\degree=\frac{x}{2.5}[/tex]
We multiply both sides by [tex]2.5[/tex] to get,
[tex]2.5\cos39\degree=x[/tex]
[tex]x=2.5(0.7771)[/tex]
We evaluate to get
[tex]x=1.94[/tex]
Therefore the length [tex]x[/tex] of the side of the triangle is [tex]1.9[/tex] units to the nearest tenth.
