Answer: 
==========================================================
Work Shown:
Focus entirely on triangle ABD (or on triangle BCD; both are identical)
The two legs of this triangle are AB = 8 and AD = 8. The hypotenuse is unknown, so we'll say BD = x.
Apply the pythagorean theorem.

So that's why the diagonal BD is exactly
units long
Side note: 
Split the triangle into a 30-60-90 triangle. Since you have LM from that triangle, you can figure out the other sides. Then, using the leg from that triangle, the one next to it is a 45-45-90 triangle, meaning it's isosceles.
KM = 30 + 10√3
KL = 10√6
(sorry i'm not too sure if my "reasons" for statement/reason is correct)
Answer:
Length = 5
Width = 21
Step-by-step explanation:
(x)(x + 16) = 105
x^2 + 16x = 105
x^2 + 16x - 105 = 0
(x - 5) x ( x + 21) = 0
x - 10 = 0
x = 5
x + 21 = 0
x = -21
Now that we have the zeroes.
We have to find the most viable one to put in.
Using -21 would not make sense, so we will use 5.
Plug it in:
x = 5
(5) (5 + 16) = 105
5 ( 21) = 105
At 45 feet depth the diver stoped the untangle the line.
Add 35 plus 10