Let's start by making sense of the relevant information. The statement tells us that the angle between and is congruent with the angle between and This means that these angles are equal in measure. Let's mark these angles in blue.
We are also given Therefore, so is
We are told that bisects This means that is divided into two equal angles. Let's mark these angles in red in our diagram.
Since and cuts this angle in half, we can conclude that is half of
Let's think back to Part B. We found that, because is a bisector We also know that is congruent to Therefore,
We are told that bisects Therefore, the angle is divided into two equal angles. Since is congruent with the following must be true. Let's mark this in our diagram.