Using a nano to control an uno

Hi, I need to use an arduino nano to turn on/off the power to a arduino uno. Would anybody have an example of how to do this?

Thanks
C

Use the Nano to control a relay (or just a transistor) that controls the power to the Uno?

It may be helpful if you explain what the overall purpose is - there may be a less expensive way to turn off an Uno.

...R

create a box with a switch.
use the UNO to turn the switch on and off

connect the NANO to the switch

if you want to turn it on and off, this might help