Two triangle ABC and EDC, are such that , $$\begin{gathered} AC=EC, BC=DC,\angle E={60}^o, \angle DCE={30}^o and \angle B={90}^o, \\ By which property in △ABC\cong △EDC? \end{gathered}$$

Using, Congruence criterion

$$\begin{gathered} Right angle, \angle B=\angle D={90}^o \\ Hypotenus,AC=EC \\ Side, BC=DC \end{gathered}$$

Hence, Triangles are congruent by RHS criterion.