The image shows a geometric problem involving parallel lines and angles. Here is the transcription of the text and the diagram:

**Text:**
```
Ax // Cy
Bly = 0
Alx 11 Cy
AB = 40°
```

**Diagram:**
```
x'
A
40°
m B
C
```

Given:
- \( Ax \parallel Cy \)
- \( AB = 40° \)

To solve the problem, we need to use the properties of parallel lines and angles. Here are the steps:

1. **Identify the given angles and lines:**
- \( Ax \parallel Cy \)
- \( AB = 40° \)

2. **Use the properties of parallel lines:**
- When two lines are parallel, the alternate interior angles are equal.
- The corresponding angles are also equal.

3. **Determine the unknown angles:**
- Since \( Ax \parallel Cy \), the angle \( AB \) (which is given as 40°) will be equal to the corresponding angle on the other side of the transversal line passing through point B.

Therefore, the angle \( \angle CB \) is also 40° due to the corresponding angles property.

So, the key takeaway is that the angle \( \angle CB \) is 40° because of the parallel lines and the properties of corresponding angles.