The angles of the four corners of the square are right angles, which means that they have a measure of 90º.
Each diagonal bisects the corner angles, this means that the diagonals divide the 90º angles into two equal angles:
[tex]\frac{90}{2}=45º[/tex]Each resulting angle measures 45º
The diagonals bisect each other so that they form 4 isosceles triangles.
The diagonals of the square are perpendicular, this means that the angles formed when they intersect each other are right angles. So the 4 central angles are right angles.
So you can conclude that the angles have the following measures:
∠AED= 90º
∠ACD= 45º
