Enter the distance between the two buoy's rounded to the nearest foot.

483 feet.

Step-by-step explanation:

Observe the triangle that is given to use. Next you want to find your adjacent, opposite, and hypotenuse of angle A. AB would be considered your adjacent because it is between angle A and your 90 degree angle, your opposite would be CB because it is directly across from angle A and AC is your hypotenuse because it is directly across your right angle.

Now with your given angle you want to use SOH CAH TOA to figure out what to use for this. You are given the length of AB, which is your adjacent. You want to also find the hypotenuse therefore you would use the CAH (Cosine, Adjacent, Hypotenuse).

You would want to then see this as cos(21.3)= with x being your hypotenuse. Now you want to get x by itself so you would then set this up as 450/cos(21.3)=x. Put this in your calculator and it would equate to 482.992 which is rounded off to 483 feet.

a. is correct