Find the value of x in the triangle shown above PLEASE HELP ASAP! Will give 5 stars to right answer

Answer:
12
Step-by-step explanation:
[tex] {9}^{2} + {x}^{2} = {15}^{2} \\ \\ 81 + {x}^{2} = 225 \\ \\ {x}^{2} = 144 \\ \\ {12}^{2} = 144 \\ \\ [/tex]