To calculate the angle between two lines, the **gradients** of the lines are needed. To get the gradient of the line, we need **two different points** and as you know, every two points in space can represent a line.

So, to get the angle of the line with the **horizontal axis**, you can use the sample below:

```
from math import degrees, atan
def calc_angle(m1, m2) -> int:
return round(degrees(atan((m1 - m2) / (1 + (m1 * m2)))))
def get_gradient(p1, p2):
return(p1[1] - p2[1]) / (p1[0] - p2[0])
def main():
p1 = (0, 10)
p2 = (10, 0)
lines_angle = calc_angle(
m1=get_gradient(p1=p1, p2=p2),
m2=0
)
print(lines_angle)
if __name__ == '__main__':
main()
```

The gradient of each horizontal line is zero so we can consider zero as the gradient of the second line.