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Determine angle $ECD$.
Mathematics 0580 · IGCSE · Circle theorems I
Circle theorems I — practice question
The diagram depicts a cyclic quadrilateral $ABCE$. $AED$ and $BCD$ are straight lines. $AC=CD$, $\angle ABC=45^{\circ}$ and $\angle ACE=20^{\circ}$. The diagram is labelled NOT TO SCALE.