Greenestamps gave you the coordinates.  Here is the 3D graph.
The shortest edges are 2, the medium sized edges are 3, and
the longest edges are 6.  

I don't know how your teacher gives the order of the vertices.
I guess B is on the x-axis, D on the y-axis and E is on the z-axis.
So you will have to supply the last 3 letters for the vertices.

G=(6,3,2) is the front upper right vertex
  (6,0,2) is the front upper left vertex
B=(6,0,0) is the front lower left vertex
  (6,3,0) is the front lower right vertex
  (0,3,2) is the back upper right vertex
E=(0,0,2) is the back upper left vertex
A=(0,0,0) is the back lower left vertex
D=(0,3,0) is the back lower right vertex

To find the distances, use



Edwin