You can key in (type in) degrees-minutes-seconds at any time- no need to change the unit display type.
The format is "XXdeg XXmin XXsec", or "XX deg XX min XX sec" WITH the spaces in between. Solid Edge will convert your entry to decimal degrees when you hit enter/tab.
will You find the "°" sign at the very upper left key (to the left of "1") with Shift ?
Here it will be on every keyboard as a standard.