I believe it has to be about-9'300
Answer:
25 miles
Step-by-step explanation:
Given: A boat sail 20 miles west of the port and then 15 miles south to an island.
Picture attached.
The distance from port to island could be measured in a straight line. It will form a hypotenous.
∴ we can use Pythogorean theorem to find the distance.

Where, "a" is adjacent= 20 miles and "b" is opposite= 15 miles.

⇒ 
⇒
⇒
We know
.
∴
∴ Distance of Port from the Island is 25 miles.
The correct answer is A. 120 ft squared because you must multiply the height times the width which comes to 120.