Find the length of the missing side

Answer:
x is 5 cm
Step-by-step explanation:
From pythogras theorem:
[tex] {a}^{2} + {b}^{2} = {c}^{2} [/tex]
a is x cm
b is 12 cm
c is 13 cm
[tex] {x}^{2} + {12}^{2} = {13}^{2} \\ {x}^{2} = {13}^{2} - {12}^{2} \\ {x} = \sqrt{ {13}^{2} - {12}^{2} } \\ x = \sqrt{169 - 144} \\ x = \sqrt{25} \\ x = 5 \: cm[/tex]