If a 1-Phase Supply is 230V, Why is 3-Phase 400V & Not 690V?

When Single Phase Supply Voltage is 220V, Why is Three Phase 440V and Not 660V? If the Single Phase supply voltage is 230V, Why is three Phase 400V and Not 690V?

AC Contactor 1NO AC 220V 50/60Hz Coil Motor Relay 32A 3-Phase-Pole J8R5

Why Three-phase Voltage is 440 Volts?

Starter Electrical Supply 20A 3 Phase Magnetic Contactor - China Magnetic Starter Price, Magnetic Starter for Air Compressor

Three phase Supplies

Is there a 690V exist in the power supply or it is just theoretical? - Quora

220V single-phase 400V 3-phase converter

Why Three-phase Voltage is 440 Volts? - Electrical Basics

Universal IE3 7.5kW Aluminium Three Phase Motor 400V/690V 2 Pole 132SX Frame B14 - AC Motors (Three Phase)

ATO 10hp Soft Starter, Three Phase Motor Soft Starters AC 220V 3 -Phase Soft Starter 7.5 kW : Tools & Home Improvement