Answer:
x = 6
Explanation:
Your triangle is a right angled triangle. So u could use the pythagorean theorem.
so,
x^2 + (x+3)^2 = 117
Then since you are given a list of answers, try substituting each value in to see what fits. In cases like this, it's easier to substitute than to try equations because u r given possible values.
Once you substitute,you'd see that x=6 works.
6^2 + (6+3)^2 = 36 +81 = 117.
Therefore x is 6
hope it helps.