4 Degrees Circle.notebook
April 20, 2017
Warm­Up: Ticket
keep radicals!
Apr 19­1:23 PM
4 Angles of Circles (Degrees)
(0,0)
The UNIT CIRCLE is a circle with center_____
origin
and radius= 1 unit
____.
y
There are ____ quadrants
in the unit circle.
There are _____ degrees
in one revolution of a circle.
Q II Q I
Q III Q IV
x
Apr 3­9:44 AM
1
4 Degrees Circle.notebook
April 20, 2017
4 Angles of Circles (Degrees)
positive x­axis "start" side The INITIAL RAY (or side) is_______________
A TERMINAL RAY is _____________________
"ending" ray of angle
Angles in the unit circle have direction.
POSITIVE angles
counter­clockwise
_____________________
NEGATIVE angles
clockwise
_____________________
Q II
Q I
Q III
Q IV
"from the center"
acute angle measured off x­axis
REFERENCE ANGLE _____________________
COTERMINAL ANGLES begin and end at
same sides
Apr 3­9:44 AM
4 Angles of Circles (Degrees)
Identify the given angles. Apr 3­9:44 AM
2
4 Degrees Circle.notebook
April 20, 2017
4 Angles of Circles (Degrees)
Identify the given angles.
NOT a
reference
NOT in
your notes
reference
Apr 3­9:44 AM
4 Angles of Circles (Degrees)
Identify the given angles.
Apr 3­9:44 AM
3
4 Degrees Circle.notebook
April 20, 2017
4 Angles of Circles (Degrees)
Draw the given angle in standard position.
190o
810o
­ 300o
Identify the reference angle.
Apr 3­9:44 AM
4 Angles of Circles (Degrees)
arc
length
θ
sector
area
Apr 3­1:37 PM
4
4 Degrees Circle.notebook
April 20, 2017
4 Angles of Circles (Degrees)
θ
Apr 3­1:37 PM
4 Angles of Circles (Degrees)
θ
30 ft
θ = _________
Apr 3­1:37 PM
5
4 Degrees Circle.notebook
April 20, 2017
4 Angles of Circles (Degrees)
Assume Earth is a sphere with radius 4000 miles. A cell phone
satellite orbits the planet 50 miles above the planet‛s surface.
It takes the satellite 18 hours to complete a full orbit.
⊕To the nearest mile, how far does the satellite travel in
one orbit?
⊕What number of degrees in 6 hours?
⊕How many miles does satellite travel in 6 hours?
⊕What number of degrees in 24 hours?
⊕How many miles does satellite travel in 24 hours?
Apr 3­1:37 PM
6