Question 7
Let $ABCD$ be a convex quadrilateral that satisfies the following conditions:
$$
\angle BAC = 2\angle BCA, \quad \angle BCA + \angle CAD = 90^\circ \quad \text{and} \quad BC = BD.
$$
Find $\angle ADB$.
$$
\angle BAC = 2\angle BCA, \quad \angle BCA + \angle CAD = 90^\circ \quad \text{and} \quad BC = BD.
$$
Find $\angle ADB$.