Answer:
x=6
Step-by-step explanation:
I would look at this triangle and notice that x can be solved by setting up a ratio.
I generally put the short side of the triangle on the top and the long side on the bottom
4/x = x/9
You then cross multiply to get 36=x^2, or +-6=x
A length of a triangle cannot be negative, so we are left with the answer x=6
