# Thread: How do I change from Radians to Degrees and vice versa?

1. ## How do I change from Radians to Degrees and vice versa?

I was sick and absent from school for the last few days and this is one of the topics that will come on the test on Thursday.

Any help would be greatly appreciated!

2. Originally Posted by Polyxendi
I was sick and absent from school for the last few days and this is one of the topics that will come on the test on Thursday.

Any help would be greatly appreciated!
Hi Polyxedni,

To change from degrees to radians, multiply degrees by $\displaystyle \frac{\pi}{180}$

Example: Change 30 degrees to radians

$\displaystyle 30^{\circ}\cdot \frac{\pi}{180}=\frac{30 \pi}{180}=\frac{\pi}{6}$ radians.

To change from radians to degrees, multiply radians by $\displaystyle \frac{180}{\pi}$

Example: Change $\displaystyle \frac{\pi}{2}$ radians to degrees

$\displaystyle \frac{\pi}{2} \cdot \frac{180}{\pi}=90^{\circ}$

3. Well there are $\displaystyle 2\pi$ radians in 360 degrees.

Use the expression: $\displaystyle 2\pi/360$.

Then you can convert back and forth.

Example - how many radians in 90 degrees?

$\displaystyle radians = 2\pi*(degrees)/360$

How many degrees in 2 radians?

$\displaystyle degrees = (radians)*360/2\pi$

Hope this helps

4. Thank you!!