Answer:
x=80
Step-by-step explanation:
This is really simple especially since you have a right triangle, you can easily determine x using trigonometry.
The cosine of an angle in a right triangle is defined by it's adjacent side divided by the hypotenuse.
[tex] \cos(50) = \frac{51}{x} [/tex]
The angle in question is 50, the hypotenuse is the side facing the 90° angle and the adjacent side is the one next to it.
By cross multiplication i can rewrite this as:
[tex]x = \frac{51}{ \cos(50) } [/tex]
[tex]x = \frac{51}{0.64278} [/tex]
[tex]x = 79.34[/tex]
Round to the nearest ten
[tex]x = 80[/tex]
