Six faces of the dice are A, B, C, D, E and F. A is adjacent to B. B is adjacent to D but not C. E is adjacent to D and F. What is the side opposite to A?

On the basis of following pattern in given dices , we can say that
Here the common faces with star and rhombus are in same positions .
From the given positions of a dice, it is clear that circle would be at the bottom, when the heart shape is at the top.

On the basis of following pattern in given dices , we can say that
The numbers 1, 3, 4 and 6 are on faces adjacent to number 5.
Therefore, 5 lies opposite 2.

On the basis of following pattern in given dices , we can say that
The numbers 1, 2, 5 and 6 are on the adjacent faces of the number 3.
So, the number 4 lies opposite 3.

On the basis of question figure pattern ,
The letters A, B, D and E are on the adjacent faces of face C.
Therefore, some other letter lies opposite 'C'.
The letters B, C and E are on the adjacent faces of face D.
Therefore, A lies opposite D.

As we can see that ,
The numbers 2, 4, 5 and 6 are on adjacent faces of the number 3.
Therefore, number 1 lies opposite to 3.
The numbers 2, 3 and 5 are on adjacent faces of the number 6.
Therefore, the number 4 lies opposite to 6.
Now, the number 5 lies opposite to 2.

According to given dice , we can say that
Two, three, four and six dots are on the faces adjacent to one dot.
Therefore, five dots are on face opposite one dot.
One dot, three dots and five dots are on the faces adjacent to two dots.
From the second view of the cube it is clear that four dots are on the face adjacent to two dots.
Therefore, six dots are on the face opposite two dots.

As per the given pattern in question figure , we can find the similar next position of given dice .
Here 2 and 4 dots are at the same side .
From figure 2 and 4 are adjacent to both 3 and 6 hence 6 will be opposite to 6. '3' lies opposite '6'.

As per the given pattern in question figure , we can find the similar next position of given dice .
From the two views of the dice it is clear that number 4 will be at the top when 3 is at the bottom.

On the basis of following pattern in given dices , we can say that
There are 2, 3, 4 and 6 dots respectively on the adjacent faces of the face having 5 dots.
Therefore, the face with one dot will be opposite the face having 5 dots.
There are 1, 3, and 5 dots respectively on the adjacent faces of the face having two dots.
Therefore, either 4 or 6 dots will be on the face opposite of the face having two dots.
Now, 4 and 6 dots cannot be on the opposite faces.
Clearly, 6 dots are there on the face opposite to the face with two dots.

On the basis of following pattern in given dices , we can say that
Here the common faces with 3 dots are in same positions .Thus , When '2' is at the bottom, number '1' will be on the top.