A birdwatcher on a cliff saw an eagle 70 feet above him. ​

Question

​
​Earlier, he had spotted the eagle 30 feet above him. ​
​
​Which integer represents the eagle's change in altitude?

A

100

B

40

C

−100 

D

−40

Answer 1

To find the eagle's change in altitude, we can subtract the earlier altitude from the later altitude.

The eagle's later altitude is 70 feet, and the earlier altitude is 30 feet.

So the change in altitude is:

Change in altitude = Later altitude - Earlier altitude
Change in altitude = 70 feet - 30 feet
Change in altitude = 40 feet

Since the altitude increased, the change in altitude is represented as a positive value.

None of the multiple-choice options indicate a positive change, but based on the calculations:

The eagle's change in altitude is \( 40 \) feet.

Thus, the answer is \( B \) \( 40 \).