To find the distance between Brianna and her hook, we need to add their distances from sea level.
Distance between Brianna and sea level = 10 1/2 feet
Distance between hook and sea level = 20 3/4 feet
To add these distances, we need to make sure they are in the same units. Let's convert the 1/2 foot to 1/4 foot so that we can add the fractions:
10 1/2 feet = 10 2/4 feet
20 3/4 feet = 20 3/4 feet (already in quarters)
Now we can add the distances:
10 2/4 feet + 20 3/4 feet = 31 5/4 feet
Therefore, the distance between Brianna and her hook is 31 5/4 feet.