SEAMO 2023 — Paper E — Grade 9–10 Question 19

In the figure, $\angle A=\angle BEF=\angle EBC=\angle ECD=90^\circ$, $\angle ABF=30^\circ$, $\angle BFE=45^\circ$, $\angle ECB=60^\circ$, and $AB=2CD$. Find $\tan\angle CDE$.