(Physics) Finding velocity with angle and speed Hi all, I'm very sorry if this is the wrong place to post a physics problem, but considering it's all maths I was hoping someone could help me. It's been a long time since I did maths on this or a similar level (nearly a decade) but I am learning physics for an exam I am planning to take this year and I have a long way to go!

I am trying to solve the a) calculation in the image.

I managed to work out the vertial (y axis) calculation. By doing: 
tan(30) on the calculator which gave 0.58 
0.58*200m/s = 115m/s

Now I have tried to do the a) calculation and I know the answer should be 231m/s as it's in the back of the book, but I don't know how to get it. The closest I've got so far is 221ms. I have been using the Khan Academy video to help me but I can't get it right - I'm so tired from trying...
http://www.youtube.com/watch?v=ZZ39o1rAZWY&amp;list=SPAD5B880806EBE0A4

Can someone explain to me clearly why it is 231m/s. I tried to figure out the time and distance like he does in the video but I wasn't getting the right answer.

Thanks!
From Pythagoras $\sqrt{115^2+200^2}\approx 231$  Similarly, $\frac {200}{\cos 30^\circ}\approx 231$
Hey I got the answer of actual velocity of missile.
Just use Pythagoras theorem in the triangle.
Let velocity of missile be $x$,so
$$X^2=(200)^2+(115)^2$$
$$X^2=40000+13225$$
$$X^2=53225$$
$$X  =230.7054$$
$$X  = 231 m/s$$