Tolong ya buat bsk hehehe makasih.

[tex]s {}^{2} = a {}^{2} + t {}^{2} \\ 12 {}^{2} = x {}^{2} + x {}^{2} \\ 144 = 2x {}^{2} \\ 2x {}^{2} = 144 \\ x {}^{2} = \frac{144}{2} \\ x {}^{2} = 72 \\ x = \sqrt{72} \\ x = 6 \sqrt{2} \: \: cm[/tex]