Here is a list of degrees to radians conversions that you need to have memorized. You need to be able to recite each one of this conversion just as you would with any degree measurement.

$$30°=\frac { \pi }{ 6 }$$ $$60°=\frac { \pi }{ 3 }$$ $$90°=\frac { \pi }{ 2 }$$ $$120°=\frac { 2\pi }{ 3 }$$ $$150°=\frac { 5\pi }{ 6 }$$ $$180°=\pi$$ $$210°=\frac{7\pi}{6}$$ $$240°=\frac { 4\pi }{ 3 }$$ $$270°=\frac { 3\pi }{ 2 }$$ $$300°=\frac { 5\pi }{ 3 }$$ $$330°=\frac { 11\pi }{ 6 }$$ $$360=2\pi$$