Answer:
4 miles
Explanation:
go down 2 miles and then going 3 miles to the right we will make the side and base of the triangle,
the missing one would be the biggest side, i.e. the hypotenuse which we will find by Pythagoras theorem,
h = √a² + b²
= √4 + 9
= √13
= 3.6 = 4
thus 4 is the full number to complete the triangle.