Yes, they are. Congruence are two objects, doesnt matter if its two dimensional or three dimensional. They are all identical in size and shape. In geometry, congruent figures have three properties: 1. The same size. 2. Same shape. 3. Parts that are corresponding are congruent. One example are ches peices, A knight is on a high shelf, the other a low shelf, Just because they are in different planes of three dimensions does NOT mean it rules out their congruence.
