Answer:
Step-by-step explanation:
pythagoras theorem
a^2+b^2=c^2
8^2+x^2=10^2
64+x^2=100
x^2=100-64
x=
x=6 km
The first option is

The second option is

So, neither of them is equivalent to 
1. Because each element in the domain is matched exactly with one element I. The range.