Hi there!
To solve this problem, we'll need to proceed methodically. First, we'll find the value of ST. Using the 30-60-90 relationship, we know that ST is equal to 2. Then, we need to find the value of RT. Again using the 30-60-90 relationship, we know that RT is equal to 4. Lastly, using the 45-45-90 relationship, we know that x = 4.
Hope this helps!! :)
If there's anything else that I can help you with, please let me know!