Exercise 2 Page 378

We know that ∠ EAC is congruent to ∠ ECA. This means that both angles have the same measure. Let's use the given information to mark the congruent angles of the given figure.

Since we have a triangle with two congruent angles, we can say that the given triangle is an isosceles triangle. We want to name two congruent segments. To do so, we will use the Converse of the Isosceles Triangle Theorem.

Using this theorem, we can identify the congruent sides.

Therefore, EA is congruent to EC. EA≅ EC

Extra

Isosceles Triangle

An isosceles triangle is a triangle that has two congruent sides called legs. The angle between these two sides is called the vertex angle and its opposite side is called the base. The angles formed by the legs and the base are called base angles. Base angles are congruent.