Fill in the blank

Question

For all three of the cubic lattices (unit cells), all of the ______ and _____ are the same size.

(body center, face center, simple cubic)

Answer 1

I think the answers probably are that the edge lengths are the same; i.e., a = b = c and all the angles are the same. The angles are 90 degrees in all cases. The way I read the question, however, it seems to ask what is true for ALL three of the cubic lattices. And the answer above doesn't fit that. If the answers above are correct then the question is poorly worded. If the answer is not correct, then I've missed the point. Post a clarification if there is more to it than that.
For simple cubic lattice, a = b = c and all angles are 90 degrees.
The same is true for face centered cubic and for body centered cubic lattices. However, it is NOT true that a, b, and c in the simple cubic, a,b, and c of the bcc and a,b, and c of the fcc are equal. It still is true that all of the angles are 90 for each and for all. I hope this helps.

Answer 2

the axes and the angles (90 degrees)