# determine the quadrant in which an angle lies. help!

#### noork85

hello u math brainiacs (Cool) i need help!

how do i go about determining which quadrant the angle lies in?

ex) -5pi/6 please explain thoroughly so i can take notes and as easy as possible because i tried and cant figure it out.

thanks!

#### Plato

MHF Helper
how do i go about determining which quadrant the angle lies in? ex) -5pi/6
$$\displaystyle \frac{-5\pi}{6}$$ is equivalent to $$\displaystyle \frac{-5\pi}{6}+2\pi=\frac{7 pi}{6}$$.
$$\displaystyle \frac{7 pi}{6}\in III$$ WHY?

#### noork85

so thats it? just find the equivalent and then locate that equivalentbon on the unit circle?

#### noork85

and what about -11pi/9 i got the answer as 7pi/9 cant locate that on the unit circle...

#### Plato

MHF Helper
and what about -11pi/9 i got the answer as 7pi/9 cant locate that on the unit circle...
Well $$\displaystyle \frac{1}{2}<\frac{7}{9}<1$$ so it is in II.

#### noork85

i understand what ur saying.

what about when im given something like just 3.5?

#### Plato

MHF Helper
i understand what ur saying.
what about when im given something like just 3.5?
If $$\displaystyle \pi<3.5<\frac{3\pi}{2}$$ in it is in III.

#### noork85

yes, ofcourse. y didnt i see that? thank you very very much!