Q:

If AB = DE CA = FD angle B is congruent to angle E angle A is congruent to angle D , then ∆ABC and ∆DEF are congruent by the ASA criterion.

Accepted Solution

A:
 1) the SAS criterion
Two triangles are congruent if they have two sides and the angle determined by them respectively equal.
AB = DE CA = FD   (two sides equal)
angle B is congruent to angle E angle A is congruent to angle D (angle determined by the two sides respectively equal)
by the SAS criterion ∆ABC and ∆DEF are congruent

2) the ASA criterion
Two triangles are congruent if they have two angles and the side common to them, respectively, equal.
angle B is congruent to angle E angle A is congruent to angle D (two angles equal)
AB = DE (the side common to the angles is equal)
by the ASA criterion ∆ABC and ∆DEF are congruent

The answer is ∆ABC and ∆DEF are congruent by the SAS criterion and by the ASA criterion