Had a test today.. Need to know if this is right.

There's a right triangle with hypotenuse 5. I forgot what term it used, but they said something about it being in between 0 and $\displaystyle \frac{\pi}{2}$

x is adjacent to theta. Find $\displaystyle sin2\theta$ I already know that $\displaystyle sin2\theta=2sin\theta cos\theta$, it's just the length of the sides I was having trouble with.

Am I correct in assuming this is just your standard 3, 4, 5 triangle and the $\displaystyle \theta = \frac{24}{25}$

There was another way I tried to solve it.. where y(opposite to theta) was = $\displaystyle \sqrt{25-x^2}$ but I didn't think that was correct so I went with the assumption I mentioned above..