ANSWER

Step-by-step explanation
We want to solve for x in the figure given.
The given triangle is an isosceles triangle, and so the perpendicular line drawn divides the line into equal halves.
This implies that we now have a right triangle as follows:
Now, we can solve for x using Pythagoras theorem:

Simplify and solve for x:
![\begin{gathered} x^2=81+400 \\ x^2=481 \\ x=\sqrt[]{481} \\ x=21.9 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/hclqq91v3mhl9yn6xrq0w2rls0brqn1pr7.png)
That is the value of x.