Since Earth has about 4 times the diameter of the Moon, the angular diameter of Earth, as seen from the Moon, is about 4 times larger than the angular diameter of the Moon, as seen from Earth. Since the Moon's angular diameter as seen from here is about half a degree, that would make Earth's angular diameter about 2 degrees.If you wish, you can look up more exact figures and do more precise calculations, but it is hardly worth the trouble, since there is some variation in the distance from Earth to Moon anyway.

Use the small-angle formula to find the angular diameter of mars when it is closest to Earth

163.36

It is true that as seen fro the earth the sun and the moon have roughly the same angular diameter. It is for that reason that total solar eclipses are so spectacular.

1/2 a degree