The answers are 0 and 2
This can be found by looking at the x axis and finding every point where the line crosses
The height of the tank is 12 inches
Answer: 
This is the same as saying 
====================================================
Work Shown:

where 
As the steps show above, the idea is to factor the radicand into smaller pieces where one of those pieces is the largest perfect square possible. In this case, 36 is the largest factor of 180 that's a perfect square. Then I used the rule
to break up the root.
The parenthesis used at the very end is to help separate the
from the
term. The "i" is not under the square root.
The anser is 11 you can see