Answer:
1. All angles are right angles, and the sides are of equal length.
Explanation:
We know that,
'Unit Cell' is a the simplest repeating unit in a crystal with parallel opposite faces and the edges connecting the equivalent points.
One of the simplest category of the unit cells is 'Cubic unit cell' which is in the form of a lattice having eight equivalent particles on the edges.
Thus, we see that,
In a cubic unit cell, all the edges have equal lengths and all the angles are right angles.
Hence, option A is correct.