Download Chapter 6A day 1 Fall 2013

trig6aday1[1]notecopy 2.notebook
September 11, 2013
Trig Chapter 6A day 1 Angles and their Measure
OBJ: - Sketch angles in standard position(degrees)
- Name coterminal angles (degrees)
- Convert between Degrees, Minutes, Seconds, and
decimal forms for Angles
From geometry: an angle is two rays with a common
endpoint.
In Trig we often use greek letters to name angles. This
angle is called theta. Others are alpha, and beta.
e
id
s
l
r
te
na
i
m
initial side
Chap 6a day1
1
trig6aday1[1]notecopy 2.notebook
September 11, 2013
In Trig when we begin our study of angles we put the
angles on a coordinate axes. The initial side is the positive
x-axis, the the terminal side can be anywhere on the plane.
These are angels in "standard position"
Positive Rotations go Counterclockwise thus resulting in
a positive angle.
Negative Rotations go Clockwise which makes the angle a
negative angle.
draw 50o and -50o
Chap 6a day1
2
trig6aday1[1]notecopy 2.notebook
September 11, 2013
Sketch the 's and name the quadrant.
ex: 345o
ex: -130o
ex: -697o
ex: 190o
clockwise rev
Chap 6a day1
ex: -190o
ex:
3
trig6aday1[1]notecopy 2.notebook
September 11, 2013
Common revolutions:
1 rev: 360o
rev: 180o
rev: 90o
rev: 60o
rev: 120o
rev: 45o
Determine the measure in o's and draw the angle in
standard position.
ex:
ex:
counter clockwise
clockwise
ex:
clockwise
ex:
counterclockwise
ex: 3.5 rev clockwise
Chap 6a day1
4
trig6aday1[1]notecopy 2.notebook
September 11, 2013
Coterminal angles: Angles with the same initial and
terminal sides.
Sketch 2 positive and 2 negative coterminal angles.
ex: 60o
Give the two smallest positive and the two largest
negative coterminal angles.
ex: 45o
ex: 425o
Find a coterminal angle such that
for 67o
Chap 6a day1
5
trig6aday1[1]notecopy 2.notebook
September 11, 2013
Degrees, Minutes, & Seconds: 60 sec(") = 1 min
60 min(') = 1 deg(o)
Hmmmmm 1o = ______sec?
Convert 50o1'21' to decimal degrees
Convert 42.501o min and sec.
Chap 6a day1
6
trig6aday1[1]notecopy 2.notebook
Chap 6a day1
September 11, 2013
7