# Python | Sympy Line.angle_between method

• Last Updated : 30 Jan, 2020
In Sympy, the function `angle_between()` is used to return the non-reflex angle formed by rays emanating from the origin with directions the same as the direction vectors of the linear entities.
```Syntax: Line.angle_between(l2)

Parameters:
l1: LinearEntity
l2: LinearEntity

Returns:

Notes: From the dot product of vectors v1 and v2 it is known that: `dot(v1, v2) = |v1|*|v2|*cos(A)`
where A is the angle formed between the two vectors. We can get the directional vectors of the two lines and readily find the angle between the two using the above formula.

Example #1:

 `# import sympy and Point, Line, pi``from` `sympy ``import` `Point, Line, pi`` ` `# using Line() method``l1 ``=` `Line((``0``, ``0``), (``1``, ``0``))``l2 ``=` `Line((``0``, ``0``), (``1``, ``1``))`` ` `# using angle_between() method``rad ``=` `l1.angle_between(l2)`` ` `print``(rad)`

Output:

`pi/4`

Example #2:

 `# import sympy and Point, Line, pi``from` `sympy ``import` `Point, Line, pi`` ` `# using Line() method``l1 ``=` `Line((``0``, ``0``), (``1``, ``0``))``l3 ``=` `Line((``1``, ``1``), (``0``, ``0``))`` ` `# using angle_between() method``rad ``=` `l1.angle_between(l3)`` ` `print``(rad)`

Output:

`3*pi/4`

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