Answer:
14 kilometers
Step-by-step explanation:
This is really about calculating perimeter.
So we need the lengths of all the sides of this right triangle.
Notice all the legs are 4 units or 4 kilometers
the hypotenuse is 4*root(2) because this is a 45-45-90 triangle.
so
Perimeter = 4 + 4 + 4
let us add: P = 4 + 4 + 4root(2) = 13.656854 km.
the nearest kilometer is 14 km.