Answer:
The answer is 72 degrees
Explanation:
The picture that Helpmetnx showed does work. But they made a mistake and assumed that the diagonal is a angle bisector, and it's not.
1. rectangle ABCD, BD & AC are the diagonals. ∠ABD =36 degrees
2. ∠ABD= ∠BDC = 36 - alternate interior angles
3. ∠DBC = 90 - 36 = 54. ∠DBC =∠ADB = ∠BCA = 54
4. Now we know that the triangle formed between the two diagonals is a isosceles triangle because of base angle theorem.
5. 180 - 54*2 = 72 degrees
I hope this helps!