For this case we have by definition, that the equation of a line in the slope-intersection form is given by:

Where:
m: It's the slope
b: It is the cutoff point with the y axis
We need two points through which the line passes to find the slope:

We found the slope:

So, the equation is of the form:

We substitute a point to find "b":

Finally, the equation is:

Answer:
Option C
x = 8.66 ft
Step-by-step explanation:
cos 30 = adj/hyp = x/10
---> x = (10 ft)cos30
= 8.66 ft
Are you looking for the length from E to F?
The answer to this question is not rational
The letter C, because the pattern is this (I think):
Every two letters it states the vowels (a,e,i,o,u)
Then in between every two letters there starts a pattern of, saying the alphabet in order and saying the alphabet backwards.
In other words they merged these two lines:
A, B, C, D, E...
+
Z, Y, X, W, V...
=
A, Z, B, Y, C, X...etc.
then by adding this pattern of vowels you get:
A, Z, E, B, I, Y, O, (C), (U), (X)...