The diagram provided asks for two angles marked as congruent. Based on the given geometry:

1. Angle $\angle GCF$ is marked congruent to $\angle DCE$**, as indicated by the identical single arc markings on both angles in the triangle portion of the diagram.

If you'd like a step-by-step explanation or further analysis of the congruence relationships, feel free to ask!

Do you want a detailed breakdown of the problem? Here are five follow-up questions to expand on this topic:

1. Why are the angles $\angle GCF$ and $\angle DCE$ congruent in this figure?
2. How can you use congruent angles to prove relationships between triangles in the diagram?
3. Are there other pairs of congruent angles or segments in the diagram? If so, what are they?
4. What does the diagram suggest about parallel lines or symmetry?
5. How could this diagram be applied to solve a problem involving triangle similarity or congruence?

Tip: Always check for geometric markings like arcs, parallel lines, or equal lengths to identify congruences or symmetries quickly!