1. **Problem statement:** Given two parallel lines $\ell \parallel m$, and $\overrightarrow{DE}$ bisects $\angle CDF$, find the value of $y$.
2. **Understanding the problem:** Since $\ell \parallel m$, alternate interior angles and corresponding angles are equal.
3. **Given:** $\angle C = 130^\circ$ (on line $\ell$), $\overrightarrow{DE}$ bisects $\angle CDF$, and we want to find $y = \angle E$.
4. **Step 1: Identify angles related by parallel lines.**
Since $\ell \parallel m$, $\angle C$ and $\angle CDF$ are supplementary because $\angle C$ is on $\ell$ and $\angle CDF$ is on $m$ with transversal $CD$.
5. **Calculate $\angle CDF$: **
$$\angle CDF = 180^\circ - 130^\circ = 50^\circ$$
6. **Step 2: Use the angle bisector property.**
Since $\overrightarrow{DE}$ bisects $\angle CDF$, it divides $\angle CDF$ into two equal angles:
$$\angle CDE = \angle EDF = \frac{1}{2} \times 50^\circ = 25^\circ$$
7. **Step 3: Find $y$.**
$y$ is the angle at $E$ adjacent to $\angle EDF$ on line $\ell$. Since $\ell \parallel m$, $\angle EDF$ and $y$ are alternate interior angles, so:
$$y = \angle EDF = 25^\circ$$
**Final answer:**
$$y = 25$$
Angle Bisector 90B75D
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