Looking at the graph, we can see that △ABC and △DEF have the same shape and size. What separates them are their position and orientation on the coordinate plane. Therefore, they are congruent.
In △ABC, vertex B is above A and C. In △DEF the corresponding vertex, F, is below D and E. To line up their orientations, we can rotate △ABC about the origin 180∘. For simplicity, and since it is not congruent to any triangle, we will not draw △GHI.
Next, by translating △A′B′C′ up 2 units and right 2 units, we can map it onto △DEF.
Therefore, the congruence transformation that maps △ABC onto △DEF is a rotation 180∘ about the origin, followed by a translation up 2 units and right 2 units. Rotation: Translation: 180∘ about the origin(x,y)→(x+2,y+2)