Find the value of the variable if the answer is not an integer leave it in its simplest form

Let us begin by redrawing the diagram for clarity:
The triangle is a right-angled triangle with the following sides:
Hypothenuse side = x
Adjacent side = 12
Opposite side = 12
To solve for x, we have to apply Pythagoras theorem which is defined as:
[tex]Hyp^2\text{ = Opp}^2\text{ + Adj}^2[/tex]Substituting and solving for x:
[tex]\begin{gathered} x^2\text{ = 12}^2\text{ + 12}^2 \\ x^2\text{ = 288} \\ x\text{ = }\sqrt{288} \\ x\text{ = }\sqrt{144\text{ }\times2} \\ =\text{ 12}\sqrt{2} \end{gathered}[/tex]Hence, the correct option is Option B