5.1 angles Flashcards
what is a ray
one point on a line and all points extending in one direction from the point
what is an angle
union of 2 rays @ a common endpoint
what is a vertex
endpoint of an angle
what are the different greek letters used in math
theta, phi, alpha, beta, gamma
what is a fixed ray
initial side
what is a rotated ray
terminal side
what is the measure of an angle
amount of rotation from the initial side to the terminal side
what does 1 degree equal
1/360
what is standard position
when the initial side is on the x-axis and the terminal side is rotated
what are the quadratic angles
0,90, 180, 270, 360
if you go counterclockwise are the angles positive or negative
positive
if you go clockwise are the angles positive or negative
negative
what is an arc
portion of a full circle
what does the length of an arc equal
the circumference
what is 2pi radians equal to
360 degrees
what is pi radians equal to
180 degrees
what does 1 radian equal to
180/ pi
what is the radian measure
angle without a unit; ratio of the length of the arc by the angle to the radius of the circle or s/r = theta
what is the formula for arc length
s = r theta
that does theta equal in arc length
s/r
what is a radian
measure of the central angle of a circle
what is a full revolution
360 degrees or 2pi
what is 1/2 revolution
180 degrees or pi
what is pi/6 eqivalent to
30 degrees
