The answer is 17! Hope it helps :)
Use a calculator called symbolab.com 0-0
Answer:

Step-by-step explanation:
Given


Required
Determine the height
The volume is calculated as:

Since, it has a triangular cross-section, the expression becomes:

So, we have:




<2 = 38
An iscolese triangle adds to 180 degrees. Thus, the two base angles, which is <2 & <3 should be half of the result from 180 - 104.
180 - 104 (angles in a triangle add to 180 degrees)
= 76
76 / 2 (iscolese triangle. base angles are equal)
therefore, 38
<span><span>θi</span>=<span>sin<span>−1</span></span>(μsin<span>θr</span>)
=<span>sin<span>−1</span></span>(1.33×sin46.5)
=74.7degrees</span>