Answer:
Half
Step-by-step explanation:
The Sun is at the center of the solar system. It is the source of heat and light. The moon revolves about the Earth while the Earth revolves about the Sun. The Sun, Earth and moon also rotate about their own axis.
The Sun illuminates half of the Moon at all times. This illuminated half does not always faces the Earth. Phases of moon are the shapes of the moon that we see from the Earth because of the portion of the illuminated part that is visible.