sorry dude thats not right. first off houses recieve AC power which cycles between positive and negative at 60hz ~120v rms in north america. they achieve a potential difference in voltage by basically taking a phase of power, splitting it into two lines and then lagging one line by 90° usually with the use of capacitance from what i was taught back in the day(Good ol ELI the ICEman). this phase shift now gives you a potential difference between those two lines of 240v and 120v between phase and ground. need to use phasor algebra with AC power. when dealing with 3 phase power you still wouldnt just add 120v plus 120v when going phase to phase, you would multiply 120v by the square root of 3 which gives you 208v.

There’s lots of pedantry going on in this thread rather than attempting to understand the spirit of the question.