* Sun's angular diameter: About 0.5 degrees
* Moon's angular diameter: About 0.5 degrees (it varies slightly due to its elliptical orbit).
While they appear to be about the same size in the sky, this is just a coincidence.
* The Sun is much, much larger than the Moon (about 400 times larger).
* The Sun is much, much farther away from Earth than the Moon (about 400 times farther).
The fact that they have similar angular diameters is why we get total solar eclipses, where the Moon perfectly covers the Sun's disk.
