Answer:
Step-by-step explanation:
I would just like to explain how this works with a visual (please enjoy my drawing <3 haha)
With my drawing we know that the bird is 150 feet above sea level, and the fish is 100 feet below sea level.
From the bird to the water it is 150 feet, from water to fish is 100 feet
From the bird to the fish it is 150 feet + 100 feet
so we know from the bird (150 feet above sea level) to the fish(100 feet below sea level).