Vamos utilizar uma regra de três simples.
Sabemos que 1π radiano equivale a 180°, então 6π/5 radianos equivalerão a:
[tex]\begin{array}{ccc}\sf Radianos&&\sf Graus\\\sf 1\pi&\sf -----&\sf 180^\circ\\\sf ^{6\pi}\!/\!_5&\sf -----&\sf x\end{array}\\\\\\\sf 1\pi\cdot x~=~180\cdot \dfrac{6\pi}{5}\\\\\\1\pi\cdot x~=~\dfrac{1080\pi}{5}\\\\\\x~=~\dfrac{1080\pi}{5\cdot 1\pi}\\\\\\x~=~\dfrac{1080\backslash\!\!\!\pi}{5\backslash\!\!\!\pi}\\\\\\x~=~\dfrac{1080}{5}\\\\\\\boxed{\sf x~=~216^\circ}~~\Rightarrow~Letra~E[/tex]
[tex]\Huge{\begin{array}{c}\Delta \tt{\!\!\!\!\!\!\,\,o}\!\!\!\!\!\!\!\!\:\,\perp\end{array}}Qualquer~d\acute{u}vida,~deixe~ um~coment\acute{a}rio[/tex]
