Since 180 degrees are the same as [tex]\pi[/tex] radians, we have the following proportion:
[tex]\text{radians angle}\div\text{degrees angle}=\pi\div180[/tex]
Since your angle, in degrees, is 60, we have
[tex]\text{radians angle}\div60=\pi\div180[/tex]
Solving for the angle in radians, we have
[tex]\text{radians angle}=\dfrac{60\pi}{180}[/tex]
Simplify this fraction and you'll get the answer.
