In Exercises 13 to $18,$ use only the given information to state the reason why $\triangle A B C \cong \triangle D B C .$ Redraw the figure and use marks like those used in Exercises 9 to 12 .
$$\overline{A C}=\overline{C D}, \overline{A B} \equiv \overline{B D}, \text { and } \overline{C B}=\overline{C B} \text { (by Identity) }$$
(GRAPH CANT COPY)