Oct 6 Angles.notebook
October 6, 2014
October 06, 2014
Monday
Types of angles
Degrees and its smaller parts
Adding and subtracting angles.
HW: Finish worksheet
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Oct 6 Angles.notebook
October 06, 2014
Angle - an angle is formed by two rays who share a common
beginning point.
1
We call this shared beginning
2
point the vertex.
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Oct 6 Angles.notebook
October 06, 2014
There are three main units of measure for an angle:
1
360
This is the unit of measure that we will be using.
4
≈ 25
of a circle
1 of a complete circle.
radian - a radian is 2π
This unit is used in upper level math classes.
mil - a mil is 1/6400 of a complete circle.
This unit is used in the military because it allows
for more accuracy.
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Oct 6 Angles.notebook
October 06, 2014
Even though 1 looks small, as we travel along a ray
farther away from the vertex, as you can see, it no
longer looks so small.
So we broke each degree into 60 equal parts, called minutes.
The symbol for a rotation unit of a minute is
= 1 degree
'
(60' = 1°)
1 of a degree.
where each minute is 60
When we add angles that are measured in degrees and minutes,
we have to remember that every grouping of 60 minutes equals
another degree.
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Oct 6 Angles.notebook
October 06, 2014
In your notebook, copy the
examples and add the angles.
Let's try some adding ...
1)
14°
+ 22°
36°
= 37°
25'
45'
70'
10'
3°
2) + 128°
58'
52'
131° 110'
= 132° 50'
How about subtracting ...
122
4)
94° 45'
22° 32'
72° 13'
5)
83
3)
114°
36°
+ 28°
178°
= 180°
= 180°
53'
49'
18'
120'
0'
or
123° 23'
24° 48'
98° 35'
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Oct 6 Angles.notebook
October 06, 2014
As we travel even farther away from the vertex (say to the
position of stars), again, even a minute gets quite big.
So we broke each minute into 60 equal parts, called seconds.
The symbol for a rotation unit of a second is
60 seconds = 1 minute
"
(60" = 1')
1 of a minute.
where each second is 60
When we add angles that are measured in degrees, minutes and
seconds we have to remember that every grouping of 60 seconds
equals another minute.
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Oct 6 Angles.notebook
October 06, 2014
In your notebook, copy the
examples and add the angles.
Let's try some adding ...
1)
63°
+ 43°
106°
= 107°
17'
52'
69'
10'
34"
28"
62"
2"
23°
2) + 174°
38' 55"
42' 4"
197° 80' 59"
= 198° 20' 59"
How about subtracting ...
24
4)
88
73° 25' 28"
12° 12' 34"
61° 12' 54"
73
5)
75
15
3)
24°
6°
+ 32°
62°
= 63°
13' 41"
0' 58"
45' 46"
58' 145"
0' 25"
65
74° 16' 5"
26° 48' 25"
47° 27' 40"
Also, if you borrow a degree so you have
enough minutes to subtract, you are
borrowing 60 minutes 1 = 60'
Remember, if you
borrow a minute so you
have enough seconds to
subtract, you are
borrowing 60 seconds.
1' = 60"
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Oct 6 Angles.notebook
October 06, 2014
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Oct 6 Angles.notebook
October 06, 2014
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