# Angle#

Qualified name: manim.mobject.geometry.line.Angle

A circular arc or elbow-type mobject representing an angle of two lines.

Parameters
• line1 (Line) – The first line.

• line2 (Line) – The second line.

• radius (float) – The radius of the Arc.

• quadrant (Sequence[int]) – A sequence of two int numbers determining which of the 4 quadrants should be used. The first value indicates whether to anchor the arc on the first line closer to the end point (1) or start point (-1), and the second value functions similarly for the end (1) or start (-1) of the second line. Possibilities: (1,1), (-1,1), (1,-1), (-1,-1).

• other_angle (bool) – Toggles between the two possible angles defined by two points and an arc center. If set to False (default), the arc will always go counterclockwise from the point on line1 until the point on line2 is reached. If set to True, the angle will go clockwise from line1 to line2.

• dot (bool) – Allows for a Dot in the arc. Mainly used as an convention to indicate a right angle. The dot can be customized in the next three parameters.

• dot_radius (float) – The radius of the Dot. If not specified otherwise, this radius will be 1/10 of the arc radius.

• dot_distance (float) – Relative distance from the center to the arc: 0 puts the dot in the center and 1 on the arc itself.

• dot_color (Colors) – The color of the Dot.

• elbow (bool) – Produces an elbow-type mobject indicating a right angle, see RightAngle for more information and a shorthand.

• **kwargs – Further keyword arguments that are passed to the constructor of Arc or Elbow.

Examples

The first example shows some right angles with a dot in the middle while the second example shows all 8 possible angles defined by two lines.

Example: RightArcAngleExample

from manim import *

class RightArcAngleExample(Scene):
def construct(self):
line1 = Line( LEFT, RIGHT )
line2 = Line( DOWN, UP )
rightarcangles = [
Angle(line1, line2, dot=True),
]
plots = VGroup()
for angle in rightarcangles:
plot=VGroup(line1.copy(),line2.copy(), angle)
plots.arrange(buff=1.5)


Example: AngleExample

from manim import *

class AngleExample(Scene):
def construct(self):
line1 = Line( LEFT + (1/3) * UP, RIGHT + (1/3) * DOWN )
line2 = Line( DOWN + (1/3) * RIGHT, UP + (1/3) * LEFT )
angles = [
Angle(line1, line2),
Angle(line1, line2, other_angle=True),
]
plots = VGroup()
for angle in angles:
plot=VGroup(line1.copy(),line2.copy(), angle)
plots.arrange_in_grid(rows=2,buff=1)


Example: FilledAngle

from manim import *

class FilledAngle(Scene):
def construct(self):
l1 = Line(ORIGIN, 2 * UP + RIGHT).set_color(GREEN)
l2 = (
Line(ORIGIN, 2 * UP + RIGHT)
.set_color(GREEN)
)
norm = l1.get_length()
a1 = Angle(l1, l2, other_angle=True, radius=norm - 0.5).set_color(GREEN)
a2 = Angle(l1, l2, other_angle=True, radius=norm).set_color(GREEN)
q1 = a1.points #  save all coordinates of points of angle a1
q2 = a2.reverse_direction().points  #  save all coordinates of points of angle a1 (in reversed direction)
pnts = np.concatenate([q1, q2, q1[0].reshape(1, 3)])  # adds points and ensures that path starts and ends at same point
mfill = VMobject().set_color(ORANGE)
mfill.set_points_as_corners(pnts).set_fill(GREEN, opacity=1)


Methods

 from_three_points The angle between the lines AB and BC. get_lines Get the lines forming an angle of the Angle class. get_value Get the value of an angle of the Angle class.

Attributes

 animate Used to animate the application of any method of self. animation_overrides color depth The depth of the mobject. fill_color If there are multiple colors (for gradient) this returns the first one height The height of the mobject. sheen_factor stroke_color width The width of the mobject.
static from_three_points(A, B, C, **kwargs)[source]#

The angle between the lines AB and BC.

This constructs the angle $$ngle ABC$$.

Parameters
• A (numpy.ndarray) – The endpoint of the first angle leg

• B (numpy.ndarray) – The vertex of the angle

• C (numpy.ndarray) – The endpoint of the second angle leg

• **kwargs – Further keyword arguments are passed to Angle

Returns

Return type

The Angle calculated from the three points

Examples

Example: AngleFromThreePointsExample

from manim import *

class AngleFromThreePointsExample(Scene):
def construct(self):
sample_angle = Angle.from_three_points(UP, ORIGIN, LEFT)
red_angle = Angle.from_three_points(LEFT + UP, ORIGIN, RIGHT, radius=.8, quadrant=(-1,-1), color=RED, stroke_width=8, other_angle=True)

get_lines()[source]#

Get the lines forming an angle of the Angle class.

Returns

A VGroup containing the lines that form the angle of the Angle class.

Return type

VGroup

Examples

>>> line_1, line_2 = Line(ORIGIN, RIGHT), Line(ORIGIN, UR)
>>> angle = Angle(line_1, line_2)
>>> angle.get_lines()
VGroup(Line, Line)

get_value(degrees=False)[source]#

Get the value of an angle of the Angle class.

Parameters

degrees (bool) – A boolean to decide the unit (deg/rad) in which the value of the angle is returned.

Returns

The value in degrees/radians of an angle of the Angle class.

Return type

float

Examples

Example: GetValueExample

from manim import *

class GetValueExample(Scene):
def construct(self):
line1 = Line(LEFT+(1/3)*UP, RIGHT+(1/3)*DOWN)
line2 = Line(DOWN+(1/3)*RIGHT, UP+(1/3)*LEFT)