The angle subtended by the Moon (diameter 3500 km) to an observer on Earth (Moon-Earth distance is about 400,000 km) is approximately:
A)1/2 degree.
B)1700 degrees.
C)1/1700 degree.
D)1/2 arcminute.

Question

Quizplus · Accepted Answer

The angle can be estimated using the small angle formula: angle in radians = diameter of the object / distance to the object. Converting the angle from radians to degrees (1 radian ≈ 57.2958 degrees), the angle subtended by the Moon is approximately 0.5 degrees.

The Angle Subtended by the Moon (Diameter 3500 Km) to an Observer