In circular measure, the value of the angle 11°15' is:

$$\eqalign{ & {11^ \circ }15' = 11 + \frac{{15}}{{60}} = 11 + \frac{1}{4} = \frac{{{{45}^ \circ }}}{4} \cr & {\text{We know }}\pi \,{\text{radian}} = {180^ \circ } \cr & {1^ \circ } = \left( {\frac{\pi }{{180}}} \right){\text{ radian,}} \cr & \frac{{{{45}^ \circ }}}{4} = \frac{\pi }{{{{180}^ \circ }}} \times \frac{{{{45}^ \circ }}}{4} = \frac{{{\pi ^c}}}{{16}} \cr} $$