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The best and most correct answer among the choices provided by the question is A </span>2.
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Hope my answer would be a great help for you. </span>
Answer:

Step-by-step explanation:
see the attached figure to better understand the problem
we know that
<em>In the right triangle ABC</em>
-----> by a 45°-90°-45° triangle
so


substitute the values

<em>In the right triangle BCD</em>

substitute the values

N=5 or n=9 can be either one
Hope this helped
X^2/a^2+y^2/b^2=1
a^2=100 a=10
b^2=64 b=8
c^2=a^2-b^2
c=6