Final answer:
AD 190 is in the 2nd century, AD 1400 is in the 14th century, and AD 2020 is in the 21st century.
Step-by-step explanation:
The Centuries of AD 190, 1400, and 2020
The year AD 190 falls within the 2nd century. To determine the century, we divide the given year by 100. Since AD 190 is greater than 100 but less than 200, it belongs to the 2nd century.
The year AD 1400 falls within the 14th century. Again, by dividing 1400 by 100, we find that it is greater than 1300 but less than 1400, placing it in the 14th century.
Lastly, the year AD 2020 falls within the 21st century. Dividing 2020 by 100, we see that it is greater than 2000 but less than 2100, indicating that it belongs to the 21st century.
Learn more about Centuries in AD