Answer:
Rotation 180° counterclockwise of orange triangle.
Explanation:
In the image attached you can observe the given parallelogram and each inner triangle.
We know by given that

Which are congruent opposite sides.
Also, side BD is the same for both triangles, so by SSS postulate those triangles are congruent.
Now, if we wanna demonstrate the congruence just using transformations, we can just rotate one triangle 180° couterclockwise, that way we will get one triangle onto the other, demonstrating their congruence.