Use the figure below to identify angles and segment lengths

So Angle GEN and FED are vertical angles, which means that their angles are congruent. Therefore, Angle FED is 60°
Angle GEN and DEN are a linear pair, which means that they are supplementary angles (add up to 180). To find Angle DEN, we have to form the equation: 60 + DEN = 180
For this, all you have to do is subtract 60 on both sides, and your answer will be: DEN = 120°
Answer:
m∠FED = 60° and m∠DEN = 120°
Step-by-step explanation:
In the figure attached,
Line segments FN and GD intersect each other at a point E forming an angle GEN = 60°
Since ∠FED ≅ ∠GEN ≅ 60° [Vertically opposite angles]
∠FED and ∠DEN are linear pairs on a line FN therefore,
m∠FED + m∠DEN = 180°
m∠DEN = 180 - m∠FED
= 180 - 60
= 120°
Therefore, m∠FED = 60° and m∠DEN = 120°