It is easy to find distances between points, lines and planes in GeoGebra. The only thing that requires a little extra work is finding the distance between a line and a plane. To find this distance, you need to find a point on the line, and insert this point using the instructions below for the distance between a point, and a point, line, or plane. This is similar to the method of doing so by hand. 
     GeoGebra Instruction 1
Algebra     View     and         3D     Graphics     under         View     in         Menu.         Note!       To         use         a         line,         it         must         be         entered         with         the         Line     command.         
Distance(<point>, <object>)
in Algebra View. Fill in your point for <point> and the point, line or plane for         <object>.         
Algebra View.         
      
     GeoGebra Instruction 2
Algebra     View     and         3D     Graphics     under         View     in         Menu.         Line     command.         This         command         has         to         be         used         in         order         for         the         Distance     command         to         work         in         the         next         step.         Distance(<line>, <line>)
Fill in the names of the two lines.
The distance is now shown in Algebra View. 
      
     GeoGebra Instruction 3
Algebra     View     and         3D     Graphics     under         View     in         Menu.         Algebra     View     using         their         equations.         Distance(<plane>, <plane>)
Fill in the names of the two planes.
The distance is now shown in Algebra View.