Answer:
+ 38,000
Explanation:
Given that:
Altitude of airplane = 38,000
The altitude of an object such as airplane in this scenario refers to the height of the airplane above sea level. The sea level is represented as a zero point (mid level) such that distance below are negative and those above are positive.
Hence, at an altitude of 38000 feets, altitude of airplane can be represented as +38,000 feets.