x

y

2C r

And because we are dealing with the unit circle here, we can say that for this special case,

2C

Remember: C

d

x

y

x

y

1r

Remember: C

d

2C

of the way around, then the length of this arc is

Since 30° is 1

12

1 12

12 12C

1

12 6C

So for any radius r when the central angle is 30° the length of the arc is… 6

r

arc length

arc length =

x

y

x

y

1r

Remember: C

d

2C

of the way around, then the length of this arc is

Since 45 is 1

8

1 12

8 8C

1

8 4C

So for any radius r when the central angle is 45

1

8 4C r

arc length

arc length =

x

y

x

y

1r

Remember: C

d

2C

of the way around, then the length of this arc is

Since 60 is 1

6

1 12

6 6C

1

6 3C

So for any radius r when the central angle is 60

1

6 3C r

arc length

arc length =

30 45 60 90

rad rad

sin

cos

6

4

3

2

Converting degrees to radians

Multiply by

Converting radians to degrees

Multiply by180

180