Question

Which phase of the moon does the figure show?

Answer 1

Since we can view Lunar phases from Earth it is determined by the orbital position of the moon in sun’s direction.

From earth one can observe each phase-in particular location of the sky.

The figure below describes the positions of an observer on earth during the day .

The position of moon in sky is related to the horizon of the observer on earth.

As lunar tangent to earth surface is at the location of the observer,Luner position can be calculated from earth.