Polar Distance is the complement of which angle?

• A. Declination
• B. Altitude
• C. Azimuth
• D. Right Ascension

Answer: (A)

Polar distance is the angular distance from an object to the north celestial pole. Declination is the angular distance from the celestial equator to the object. Since the arc from the celestial pole to the celestial equator is 90 degrees, the two angles add up to 90 degrees: polar distance = 90° − declination. So the polar distance is the complement of the declination.

That’s why the correct choice is the one describing declination. The other terms refer to different measures: altitude is height above the horizon, azimuth is compass direction along the horizon, and right ascension is a time-based longitude along the celestial equator.