Solving a relatively easy trig. equation...

Hi!

The equation is...

i'm trying to solve for theta, limiting domain from 0 to 360 degrees.

After substituting for and simplifying i ended up with...

OR

after applying arcsine i came up with an answer of 0 degrees. Now, my graphing calculator of course does not provide ALL possible answers. I noticed that 180 degrees is also an answer. I guess this is because of the theoretical -0 degrees that when squared would result in 0 too?

Did i do this correctly?