Fibonacci is famous for his contributions to number theory.
In his book, Liber abaci he introduce the Hindu-Arabic place-valued decimal systems and the use of Arabic Numerals into Europe.He introduced the bar we use in fractions, previous to this, the numerator has quotations around it. The square root notation is also is Fibonacci method.
84 miles.
You just have to take half of 56 (28) and add it to 56 to get 84
I think you need to retype this one. The formatting makes this question difficult to understand.
Answer:
Pythagorean theorem, eh?
Step-by-step explanation:
The way to do this is use the radius-tangent angle theorem thing...
It states that, a radius that intersects a point of tangency(I think that's what it's called) is perpendicular to the tangent. Thus, CW is perpendicular to OW!
Thus, it forms a right triangle, where we can use Pythagorean Theorem!
If you don't know what it is, check the internet! It's pretty simple.

So, there you go! Hope this helps!
NOTE: This answer was recently deleted for violating community guidelines, so I just re-uploaded it!(and edited it) So if you do need more help, do some research!