How do you convert -3.5 to degrees?

1 Answer
Aug 3, 2015

use the conversion pi=180

Explanation:

-3.5 is a radian measure which needs to be converted to degrees.

for that we need a simple conversion factor: pi=180

Now we are going to setup an equation with the conversion factor. A nice way to do this is to take advantage of the proportionality of the problem. So we set the equations up like this:

-3.5 = x in the same proportion as pi=180

-3.5/pi=x/180

to solve we simply undo the division on x with a multiply

180*-3.5/pi=x

-630/pi=x
now it is a matter of how many decimals. Let us say that we are using the standard 3.14 approximation and need two decimal places.

-630/3.14=x
x=-200.64
(we changed the direction at the end to follow convention)

this should make sense because 3.5 is a little bigger than 3.14 and 200 is a little bigger than 180. And don't forget the sign!

NOTE: always put the same units in the same fraction
(rad)/(rad)=(degrees)/(degrees)

and that makes us happy. :)