1. 6.1 Angles and Their Measure
θ: the Greek letter theta, which is used as a variable for angle measurement.
degree (°): 1/180 of a straight angle
minute(‘): 1/60 of a degree
second(“): 1/60 of a minute
DMS: the use of degrees, minutes, and seconds as opposed to decimal degree measure.

2. Converting Between DMS And Decimal
To convert to DMS, take the decimal part of the angle and multiply by 60. The new whole number is the minutes, multiply the new decimal part by 60 to get the seconds.
To convert from DMS, divide minutes by 60 and seconds by 3600 and add fractions to the whole number of degrees.

3. Example 1: Converting to DMS
Convert ° to DMS.

4. Example 2: Converting from DMS
Convert 13° 12’ 54” to decimal notation.

5. What is a Radian???
radian: the angle measure of a central angle where the radius and arc length are the same.

6. Angle Conversions To convert radians to degrees, multiply by
To convert degrees to radians, multiply by

7. Example 3: Angle Conversion
Convert 34° to radians.

8. Example 4: Angle Conversion
convert to degrees

9. Arc Length
Radian Measure:
Degree Measure:
r = radius of circle

10. Example 5: Arc Length
Find the perimeter of a 60° slice of a 12in. diameter pizza.

11. 6.1 HW Assignment
Pg. 365 #s evens, evens