Answer:
The given triangle is a right triangle.
The length of the hypotenuse is 2.52.5 units.
The given angle is 39\degree39° .
The unknown side xx is adjacent to the given angle.
We can therefore use the cosine function to find xx .
Recall the mnemonics CAH.
This means that;
\cos\theta=\frac{Adjacent}{Hypotenuse}cosθ=
Hypotenuse
Adjacent
This implies that,
\cos39\degree=\frac{x}{2.5}cos39°=
2.5
x
We multiply both sides by 2.52.5 to get,
2.5\cos39\degree=x2.5cos39°=x
x=2.5(0.7771)x=2.5(0.7771)
We evaluate to get
x=1.94x=1.94
Therefore the length xx of the side of the triangle is 1.91.9 units to the nearest tenth.
