SOLUTION: An arc of a circle measures 72 degrees. If the radius of the circle is 6cm, about how long is the arc?

For any arc of the radian measure    (in radians),  its length is  ,  where "r" is the radius of the circle.


So, convert 72 degrees to radians and use this formula.


Alternatively, you may notice that 72 degrees is    of the full angle of 360 degrees,

so 72 degrees is    of  radians:  72 degrees =  radians.


THEREFORE, the arc length is   =  = 7.536 cm.    ANSWER