The figure below represents a triangular flower garden ABC in which AB = 4m, BC = 5and ∠BCA =30 degrees . Point D lies on AC such that BD = 4 m and ∠BDC is obtuse.

Find, correct to 2 decimal places:
Stuck on both. how to get law of sin.
(a) the length of AD;
(b) the length of DC;

Took me a while to find it, but I answered this question for you 3 days ago

https://www.jiskha.com/questions/1813064/triangular-flower-garden-abc-in-which-ab-4m-bc-5and-bca-30-point-d-lies-on-ac