Option 1 : \(\dfrac{\pi }{5}\)

__Concept__:

**Relationship between Degree and Radian**:

- To convert x
**radian into degree**multiply x by \(\dfrac{{180}}{\pi }\) - To convert x
**degree into radian**multiply x by \(\dfrac{\pi }{{180}}\)

__Calculation__:

Here, we have to convert 36° into radian.

As we know that, in order to convert x **degree into radian** we have to multiply x by \(\dfrac{\pi }{{180}}\)

\(\Rightarrow 36^\circ = \left( {\dfrac{\pi }{{180}} \times 36} \right)\;\text{radian} = \dfrac{\pi }{5}\; \text{radian}\)