find the missing side of the triangle.

Answer:
Step-by-step explanation:
A=2 ,B=4 ,C=?
[tex]C^{2}[/tex]=[tex]A^{2}[/tex]+[tex]B^{2}[/tex]
[tex]C^{2}[/tex]=[tex]2^{2}[/tex]+[tex]4^{2}[/tex]
[tex]C^{2}[/tex]=4+16
[tex]C^{2}[/tex]=20
C=[tex]\sqrt{20}[/tex]