congruent
adj.describing two shapes that are exactly the same in size and shape. You can move or turn one to fit perfectly on top of the other.
adj.identical in form; coinciding exactly when superimposed. In mathematics, it describes geometric figures that have the same shape and size, or in logic, statements that are consistent with one another.
“The two triangles are congruent because they have the same side lengths.”
“The architect ensured that the two wings of the building were congruent to maintain a symmetrical appearance.”
“In formal logic, a set of axioms is considered congruent if no two statements within the set can be simultaneously true without contradicting the others.”
From Middle English congruent, from Latin congruēns, present active participle of congruō (“meet together, agree”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.