Decimal degrees (DD) is a way of expressing latitude and longitude geographic coordinates as decimal fractions (e.g 54.135°) and an alternative to the more common format of Degrees, Minutes, and Seconds (DMS). But there are many times when you are supplied with latitude and longitude coordinates in decimal degrees but you need them to be in Degrees, Minutes, and Seconds.
There are several easy solutions that you can use:
When you only have a few values then using a free online converter is a pretty good option,
when you have no Internet access, like times when you are in the field, then you could use the formula as it is relatively simple (Decimal Degrees = Degrees + minutes/60 + seconds/3600),
or if you have lots of values to convert, then you can be easily adapt a spreadsheet to become a great little converting tool.