Step-by-step explanation:
By using formula of h^2=p^2+b^2
h=20
p=x
b=10
Now,
p=root h^2-b^2
x=root 20^2-10^2
x=root 400-100
x=root 300
x= 10root3
10 * 0.1 = 1
100 drops is 1 fluid ounce.
For this case we must find the perimeter of the fence, in a circular way, knowing that the perimeter of a circle is given by:

Where "r" represents the radius of the circle, in this case 
Substituting in the perimeter equation we have:

Rationalizing we have:

Taking out common factor
:

Answer:

Option C
Cool. Is there a question though