circle geometry

i'm pretty sure that angle ROS is 2 times angle RTS (correct me if i am wrong).

 

so, we can craft an equation that looks like this:

 

16x - 4 = 2(7x + 5)

16x - 4 = 14x + 10

2x = 14

x = 7

 

now we plug x back into our expression for angle RTS.

 

7(7) + 5 = 49 + 5 = 54 

 

hope this helped! if you are confused on how i did anything, please let me know! :)