DK-GEORGMOHR 1997 Problem 3

About pentagon $ABCDE$ is known that angle $A$ and angle $C$ are right and that the sides $| AB | = 4$ , $| BC | = 5$ , $| CD | = 10$ , $| DE | = 6$ . Furthermore, the point $C'$ that appears by mirroring $C$ in the line $BD$ , lies on the line segment $AE$ . Find angle $E$ .