Source: http://www.schooltube.com/video/010e4e6376a7485a8e72/Arc%20Length%20and%20Area%20of%20a%20Sector
This is a video showing some examples on finding arc length and sector area.
Source: http://www.schooltube.com/video/6cfceed58faf484cbc44/Circles%20-%20Arc%20Length%20and%20Area%20of%20Sectors