We can see here two triangles, and we can notice the following:
1. Since H is the midpoint of the segment EG, we can say that EH and HG are congruent segments.
2. Since these two triangles, namely, EFH and GFH share the same segment (HF), this side is also congruent to these two triangles.
3. Since EH is congruent to HG, and FH is congruent to itself, then EF is congruent to GF.
4. Angle E is congruent to angle G.
Therefore, we can say that:
Since we have that:
a. EF is congruent to GF
b. EH is congruent to GH
c. Angle E is congruent to angle G
We can conclude that the congruence rule, in this case, is SAS (Side-Angle-Side), because if two sides and the included angle are congruent to the corresponding parts of the other triangle, the triangles are congruent.
We also see that the three sides are congruent (and in this case, we can also conclude that the triangles are congruent by the rule SSS (side-side-side).
Likewise, we can also conclude that the triangle EFH is congruent to triangle GFH.