MathNet 2018-part-01 — 181 problems (EN–VI) Question 132

Given the isosceles triangle $ABC$ ($CA = CB$). The bisector of the angle $\angle B$ intersects the side $AC$ at point $L$ and the circumcircle of the triangle $ABC$ at point $D$. It is known that $\angle C \gt 60^\circ$.
Prove that $DC + DL \le BC$.