Can someone help me? I dont really know how to do this?

Answer:
The answer is 54.
Step-by-step explanation:
Ok buddy
‣Remember that a right angle equals 90 degrees.
‣The numbers lie on a right angle.
‣So watchya gonna do is combine the like terms.
[tex]x + 2x + 2x = 5x[/tex]
‣In an equation, that finna look like:
[tex]5x = 90[/tex]
‣Solve that equation
[tex] \frac{5x}{5} = \frac{90}{5} \\ \\ x = 18[/tex]
‣Therefore, the value of x is 18.
‣We trynna find 3x so plug it.
[tex]3x \\ 3(18) \\ 54[/tex]
‣That fr is the answer, 54.