Video Transcript
Which of the following is the
definition of an angle? Option (A) it is the rotation
of a point from one position to another around a line segment. Option (B) it is the rotation
of a ray from one position to another around the starting point. Option (C) it is a measure of
the distance between two points. Option (D) it is a quantity
that measures how many points two lines intersect at. Or is it option (E) it is the
rotation of a line segment from one position to another around a ray?
In this question, we are asked
to identify which of five given options is the correct definition of an
angle. We can do this by recalling
that an angle is the rotation needed to rotate one ray onto another ray that
share the same initial point. We call the shared initial
point the vertex of the angle. In particular, we call the
rotation needed to rotate one ray onto the other the angle at the vertex. We can see that this matches
option (B).
We can also note that we only
define rotations in the plane around a point, so options (A) and (E) cannot be
correct. Similarly, option (C) is the
length of a line segment from its endpoints.
