What is the correct phrase?

[dchianel]

Is the correct phrase, he did a 360, or is it he did a 180?

[GJ911S]

It's he did a 180. To do a 180 is to do an about face on an opinion or a course of action. Tha number 180 refers to the "180" degree point of a circle, or the point opposite of the "0" degree point of the same circle. White is to black or sweet is to sour, ect....

[jan15]

Both are used.

Doing a 180 suggests turning around and going the other way, usually in the sense of a car making a u-turn, but also by association it can mean changing one's plans.

Doing a 360 refers to something that race car drivers sometimes do as part of an accident and stunt drivers routinely do intentionally, spinning a car completely around at high speed without decreasing forward momentum.