The maximum length of the poster that can be put in the box is [tex]28in[/tex].
In a cuboid, the longest dimension is the diagonal of the cuboid.
Diagonal = [tex]\sqrt{(length)^{2}+(width)^{2}+(height)^{2} }[/tex]
Let, [tex]l=[/tex] the length of the cuboid
[tex]b=[/tex] the width of the cuboid
[tex]h=[/tex] the height of the cuboid
And [tex]d=[/tex] the diagonal of the cuboid
So, as per the formulae [tex]d=\sqrt{l^{2}+b^{2}+h^{2} }[/tex]
Assigning the given values,
[tex]l=24[/tex]
[tex]b=8[/tex]
[tex]h=12[/tex]
Now, calculate [tex]d[/tex] using the formulae,
[tex]d=\sqrt{24^{2}+8^{2}+12^{2}}=\sqrt{576+64+144}=\sqrt{784}=28[/tex]
Hence, the maximum length of the poster that can be put in the box is [tex]28in[/tex].
Learn more about the cuboid here-https://brainly.com/question/9740924
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