There are two systems for measuring angles: degrees and radians. Degrees have the unit symbol ° while radians are unitless. A full circle is equal to 360° or 2π radians. To convert between the two units, degrees can be converted to radians by multiplying by π/180 and radians can be converted to degrees by multiplying by 180/π.

1. Measurement of Angles
2 Systems
- unit symbol is
o
- has no unit symbol
us -r
r a di
= arc length = s
The central angle is subtended or "covered" by an arc length
(for a given radius)
C=2 r
in rads = rads or radians
or 2 (3.14) = 6.28 rads

2. The Connection -> Rads to Degrees
Degrees Radians
(exact values)

3. Converting Degrees Radians
ex 1) How many radian is
(in -terms)

4. ex 2) How many degrees is