Answer:
23358.1
Step-by-step explanation:
216.2
[tex]a^2+b^2=c^2\\\\c=3959+5.9\\\\b=3959\\\\a=x\\\\\\(x)^2+(3959)^2=(3964.9)^2\\\\x^2=(3964.9)^2-(3959)^2\\\\x^2=(3964.9-3959)(3964.9+3959)\\\\x^2=5.9(7923.9)\\\\x\approx 216.2[/tex]