Final answer:
To prove triangles congruent, one method is using the Side-Angle-Side (SAS) congruence criterion. This states that if two sides and the included angle of one triangle are congruent to the corresponding sides and included angle of another triangle, then the triangles are congruent.
Step-by-step explanation:
To prove triangles congruent, there are several methods that can be used. One common method is using the Side-Angle-Side (SAS) congruence criterion. This states that if two sides and the included angle of one triangle are congruent to the corresponding sides and included angle of another triangle, then the triangles are congruent.
For example, in the given problem, triangles GFC and AHD can be proven congruent using SAS since they have the same side lengths and the included angle at C is the same.
Remember to provide specific measurements or information from the problem in your proof to support the congruence criterion being used.