Final answer:
The angle measure between point A and the northern horizon can be found using the concept of elevation. For example, on December 21, as seen from a place on the Tropic of Cancer, the altitude of the Sun at noon would be 23° below the zenith (90°), therefore the angle measure between point A and the northern horizon can be calculated as 90° - 23° = 67° above the horizon.
Step-by-step explanation:
The angle measure between point A and the northern horizon can be found using the concept of elevation. Elevation is the angle by which an object is lifted above the horizontal. In this case, the northern horizon corresponds to the celestial equator. The altitude of the Sun at noon on a specific date can provide the angle measure above the horizon. For example, on December 21, as seen from a place on the Tropic of Cancer, the altitude of the Sun at noon would be 23° below the zenith (90°). Therefore, the angle measure between point A and the northern horizon can be calculated as 90° - 23° = 67° above the horizon.