Answer:
2155.1 m^3
Step-by-step explanation:
area= pi* r ^2 * h =pi * 7^2 *14 = 2155.1 m^3
20 feet should be the correct answer. not sure if there's any choices
Notice that our function

is a parabola, and the vertex form of a parabola is:

where (h,k) are the coordinates of its vertex.
The first thing we need to do is find the vertex (h,k) and to do that we are going to use the vertex formula:

, and then we are going to evaluate our function at

to find

.
We know for our problem that

, and

, so lets replace those values in our vertex formula to find

:




Now, we are going to evaluate our function at -6 to find

:



Now that we have our vertex, where

and

; lets replace those values in our vertex form equation:
![f(x)=-5[x-(-6)]^{2} +(-1)](https://tex.z-dn.net/?f=f%28x%29%3D-5%5Bx-%28-6%29%5D%5E%7B2%7D%20%2B%28-1%29)

We can conclude that the vertex form of our function is

, and its vertex is (-6,-1).
7 is

miles; the question includes the words "in all", which shows that the two fractions should be added together. To add fractions with the same denominator, you must simply add the numerators and keep the denominator unchanged.
8 is

yards of ribbon; this one also requires you to add the fractions-- the numerators should be added, but the denominator stays the same because the two fractions share the same denominator.