Because it occurs at the time that's either 1/4 or 3/4 of the way
through the full cycle of phases between two New Moons.
The phase that comes before the last quarter is called the waning gibbous.
first or last quarter
The phase where the moon looks like a semicircle is called the "first quarter" or "last quarter," depending on its position in the lunar cycle. In the first quarter phase, half of the moon's surface is illuminated and visible from Earth, appearing as a right half. In the last quarter phase, the left half is illuminated. Both phases showcase a semi-circular appearance of the moon.
We see a Half Moon illuminated. The name of this phase is called Last Quarter. First Quarter is 1 week before a Full Moon.
We see a Half Moon illuminated. The name of this phase is called Last Quarter. First Quarter is 1 week before a Full Moon.
The moon cycles through 4 phases every month. There are about 3 weeks between the first and last quarter phases of the moon.
The phase of the moon is called a first quarter or last quarter moon when it appears as a semi-circle. This occurs when the moon is at a 90-degree angle relative to the Earth and the Sun, resulting in half of the illuminated side facing Earth.
In the first quarter moon, the round portion of the visible moon faces west (forming the letter D when viewed in the northern hemisphere). In the last quarter phase the round portion faces west.
I believe that the anwser is last quarter.
New moon."New Moon" follows "waning crescent"New Moon
first or last quarter
New moon, first quarter, full moon and third quarter