Answer:
b = 8
Step-by-step explanation:
Using Pythagorean Theorem, a[tex]a^{2} +b^{2} =c^{2}[/tex], we just plug in what we know.
We know that the hypotenuse, c, is 10 km. We also know that one of the other side lengths is 6 km, we can plug that into either a or b.
Now, our equation will be: [tex]6^{2} +b^{2} =10^{2}[/tex].
You could also use the equation: [tex]b^{2} =10^{2} -6^{2}[/tex].
Next, we'll just solve the equation.
[tex]10^{2} =100[/tex], [tex]6^{2} = 36[/tex]
[tex]b^{2} =100 - 36[/tex]
[tex]b^{2} = 64[/tex]
[tex]\sqrt{b^{2} } = \sqrt{64}[/tex]
b = 8
Good luck :D