Answer:
8.9miles
Explanation:
Kindly find attached a rough sketch of the dog's movement.
Step one:
given data:
let the movement southeast be x,=3.5miles
and let the movement northeast be y=8.2 miles
let the resultant be z
Step two:
The resultant vector can be found using the Pythagoras theorem
z^2=x^2+y^2
z=√x^2+y^2
substituting we have
z=√3.5^2+8.2^2
z=√12.25+67.24
z=√79.49
z=8.9miles