(l1, l2)
return C.acos(v1.dot(v2)/(abs(v1)*abs(v2)))
The angle formed between the two linear entities.

        Parameters
        ==========

        l1 : LinearEntity
        l2 : LinearEntity

        Returns
        =======

        angle : angle in radians

        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.

        See Also
        ========

        is_perpendicular

        Examples
        ========

        >>> from sympy import Point, Line
        >>> p1, p2, p3 = Point(0, 0), Point(0, 4), Point(2, 0)
        >>> l1, l2 = Line(p1, p2), Line(p1, p3)
        >>> l1.angle_between(l2)
        pi/2
The angle formed between the two linear entities.
The angle formed between the two linear entities .
def angle_between(l1, l2):
        """The angle formed between the two linear entities.

        Parameters
        ==========

        l1 : LinearEntity
        l2 : LinearEntity

        Returns
        =======

        angle : angle in radians

        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.

        See Also
        ========

        is_perpendicular

        Examples
        ========

        >>> from sympy import Point, Line
        >>> p1, p2, p3 = Point(0, 0), Point(0, 4), Point(2, 0)
        >>> l1, l2 = Line(p1, p2), Line(p1, p3)
        >>> l1.angle_between(l2)
        pi/2

        """
        v1 = l1.p2 - l1.p1
        v2 = l2.p2 - l2.p1
        return C.acos(v1.dot(v2)/(abs(v1)*abs(v2)))
def angle_between ( l1 , l2 ) : v1 = l1 . p2 - l1 . p1 v2 = l2 . p2 - l2 . p1 return C . acos ( v1 . dot ( v2 ) / ( abs ( v1 ) * abs ( v2 ) ) )