METHOD
1: Eliminate possibilities:
The letter A is adjacent to B, C, E, and F.
The remaining letter, D,
must be opposite A.
METHOD 1: Create a net diagram: Start
with A. From the first view, C is directly below
and oriented the same as A, while B is to A's right
and rotated counterclockwise 90 degrees. From the
third view, F is directly above A and oriented the
same as A, while E is to A's left and rotated clockwise
90 degrees. From the second view, D is directly
above F and oriented the same as F, while E is to
D's left and rotated counterclockwise 90 degrees.
D is the only face two away from A. D is opposite
A.
Followup:
How many faces of an opaque cube can be seen at
one time? (1, 2, or 3)

