What are the altitude and azimuth (in degrees)of a star that is setting in the southwest?
A)Altitude 90,azimuth 90
B)Altitude 30,azimuth 180
C)Altitude 0,azimuth 240
D)Altitude 45,azimuth 360

Question

Quizplus · Accepted Answer

When a star is setting in the southwest, it means it's getting closer to the horizon and its altitude is decreasing. Therefore, the altitude cannot be 90 or 45. 
Since it's setting in the southwest, its azimuth value should be between 180 and 270. The only option that fits both criteria is C, with an altitude of 0 (on the horizon) and an azimuth of 240 degrees (toward the southwest).

What Are the Altitude and Azimuth (In Degrees)of a Star