what is the shape of a crescent moon
Crescent The crescent shape consists of a circular disk with a segment of another circle removed from its edge, so that what remains is a shape enclosed by two circular arcs of different diameters which intersect at two points (usually in such a manner that the enclosed shape does not include the center of the original circle). As such, it belongs to the class of figures known as lune in planar geometry. The tapering towards the points of intersection of the two arcs are known as the "horns" of the crescent. The classical crescent shape has its horns pointing upward (and is often worn as horns when worn as a crown or diadem, e.g. in depictions of the lunar goddess, or in the headdress of Persian kings, etc.[7]
Orbit of the Moon The Moon orbits Earth in the prograde direction and completes one revolution relative to the stars in about 27.32 days (a sidereal month) and one revolution relative to the Sun in about 29.53 days (a synodic month). Earth and the Moon orbit about their barycenter (common center of mass), which lies about 4,600 km (2,900 mi) from Earth's center (about 3/4 of the radius of Earth). On average, the distance to the Moon is about 385,000 km (239,000 mi) from Earth's center, which corresponds to about 60 Earth radii.