The correct answer is:
They can share 0, 1 or 2 sides.
Step-by-step explanation:
Congruent angles have the same measure. This means the distance between their two sides is the same.
We can have two angles that are not attached that are congruent.
We can have two angles that share one side that are congruent.
We can also have two angles that are on top of each other, sharing 2 sides, that are congruent.