7.1 Flashcards
Angles and Their Measure
Ray
portion of a line that starts at a point V on the line and extends indefinitely in one direction.
Vertex
The starting point V of a ray.
Angle
Formed by two rays drawn with a common vertex.
Two rays of an angle are ________ and ______.
Initial side, terminal side.
If the rotation is counterclockwise the angle is _______.
Positive.
If the rotation is clockwise the angle is _______.
Negative.
Standard Position:
Vertex is at the origin of a rectangular coordinate system and its initial side coincides with positive x axis.
When the terminal side lies on the x or y axis it is a ______.
Quadrantal angle.
Right Angle:
90°
Straight Angle:
180°
One minute 1’ =
1/60°
One second 1” =
1/3600°
Central Angle
positive angle whose vertex is at the center of a circle.
Arc Length
s=rtheta
360° = ______ radians
2π
