Solution
For this case we have a right triangle
The angle given is 39º
The adjacent side = 7
And we want to find the value of the hypothenuse x, we can use the following identity:
[tex]\text{cos}39=\frac{7}{x}[/tex]Solving for x we have:
[tex]x=\frac{7}{\cos 39}=9.007[/tex]The answer rounded to the nearest tenth would be:
9.0