Question

Who can help me ! .... thanks

Answer 1

Given that there is no any option to choose I am going to help you according to the concepts of Congruent Triangles. Two triangles are congruent if and only if:

1. They have:exactly the same three sides
2. exactly the same three angles.

There are five ways to find if two triangles are congruent but in this problem we will use only two.


First Answer:

ASA criterion: Angle, side, angle. This means that we have two triangles where we know two angles and the included side are equal.

So:

If ∠BAC = ∠DEF and $\overline{AC}=\overline{DE}$

Then ΔABC and ΔEFD are congruent by ASA criterion.

Second answer:

SAS criterion: Side, angle, side. This means that we have two triangles where we know two sides and the included angle are equal.

$If \ \overline{AC}=\overline{DE} \ and \ \overline{BC}=\overline{DF}$

Then ΔABC and ΔEFD are congruent by SAS criterion.