initial side
The ray where measurement of an angle starts.
In geometry, an initial side is the starting position of a ray or line segment in the coordinate plane. It is the endpoint of the segment or ray that is labeled initial. The position of the initial side is usually defined in terms of its coordinates on a coordinate plane.
For example, if we have a ray that starts at point A(3, 4) and extends in the direction of point B(7, 2), then the initial side of the ray is located at point A(3, 4). Similarly, if we have a line segment that starts at point C(1, 1) and ends at point D(5, 3), then the initial side of the segment is located at point C(1, 1).
Knowing the position of the initial side is important because it helps us define the direction and length of the segment or ray. It also helps us calculate measurements such as angle measures and distances.
More Answers:
Understanding Positive Angles: Measuring Counterclockwise from the Initial Side.Understanding the Importance of Standard Position in Mathematics: A Guide to Accurate Geometric Measurements and Calculations
Understanding Terminal Sides in Standard Position for Angles in Mathematics