The following triangles are congruent because both show

SAS property

Explanation

We will show that two sides and the angle between them in one triangle are congruent, respectively, to two sides and the angle between then in a second triangle.  Then we know that the two triangles are congruent by the SAS property.

Since vertical angles are congruent,

∠1 ≅ ∠2

From the figure, we see that 

\( \overline{AC} \cong \overline{EC} \) and \( \overline{BC} \cong \overline{DC} \)

Since two sides and the angle between then in one triangle are congruent, respectively, to two sides and the angle between then in a second triangle, \( \triangle ABC \cong \triangle EDC \) by the SAS property.