Greatest common factor of 12 , 16,and20

4 is your greatest common factor

4

have a goed day

oh and btw idk if dis is history

ill take da crown

there are two main types of historical sources: primary sources and secondary sources. a primary source is something that originates from the past. it can be a chronicle, a piece of pottery, or even a piece of glacial ice that gives us climate data about the levels of atmospheric carbon one thousand years ago.

sonar maybe? ? i dont know the choices