Answer:
B
Step-by-step explanation:
This uses the pythagorean theorem, a^2+b^2=c^2. Knowing that c^2 is always across from the right angle(shown with the small square) the 18 mi can be represented by a and the 24 mi can be represented by b. 18^2+24^2=900. We now know that c^2=900 the opposite action of ^2 is the square root, so we square root 900 to get the final answer which is 30.B
