C:\>where flutter dart

C:\dev\src\flutter\bin\flutter
  C:\dev\src\flutter\bin\flutter.bat
  C:\dev\src\flutter\bin\dart
  C:\dev\src\flutter\bin\dart.bat
  C:\dev\src\dart-sdk\bin\dart.exe

However, if you are using PowerShell, in it where is
  an alias of Where-Object command, so you need to use where.exe instead.

PS C:\>

where.exe flutter dart

To learn more about the dart command, run dart -h
  from the command line, or see the dart tool page.

Run flutter doctor

From a console window that has the Flutter directory in the
path (see above), run the following command to see if there
are any platform dependencies you need to complete the setup:

C:\src\flutter>flutter

doctor