SEAMO 2027 - Paper F - SET 01 - Self-study Question 19

In quadrilateral $ABCD$, diagonals $AC$ and $BD$ intersect perpendicularly at $P$. If $\angle BAC=30^\circ$, $\angle ACD=60^\circ$ and $\angle ADB=20^\circ$, find $\angle ABC$ in degrees.

Use the convex quadrilateral shown: $P$ is inside both diagonal segments.