Answer:
12[tex]\sqrt{2}[/tex]
Step-by-step explanation:
The single line through the two side indicate those lines are the same
Use Pythagorean theorem:
[tex]a^{2} + b^{2} = c^{2} \\12^{2} + 12^{2} = x^{2}[/tex]
144 + 144 = [tex]x^{2}[/tex]
288 = [tex]x^{2}[/tex]
[tex]\sqrt{288} = \sqrt{x^{2} }[/tex]
x = 12 [tex]\sqrt{2}[/tex]
