We prove that,
by using Angle-Side-Angle (ASA) congruence theorem.
The given diagram shows a triangle with a missing angle. The triangle is labeled
, and the missing angle is
. The diagram also shows a line segment
that intersects
at point E and
at point F.
To prove that
, we can use the Angle-Side-Angle (ASA) congruence theorem. The ASA congruence theorem states that two triangles are congruent if they have two congruent angles and a congruent side between the angles.
In
and
, we have the following congruences:
-
(given)
-
(given)
- AC = EF (segments opposite congruent angles in a triangle are congruent)
Therefore, by the ASA congruence theorem, we can conclude that
.