Question 59
Let $ABCD$ be a convex quadrilateral with
$$
\begin{aligned}
\angle CBD &= 2 \angle ADB, \\
\angle ABD &= 2 \angle CDB \\
\text{and}\quad AB &= CB.
\end{aligned}
$$
Prove that $AD = CD$.
$$
\begin{aligned}
\angle CBD &= 2 \angle ADB, \\
\angle ABD &= 2 \angle CDB \\
\text{and}\quad AB &= CB.
\end{aligned}
$$
Prove that $AD = CD$.