Answer:
[tex]W=21\ in[/tex]
Step-by-step explanation:
we know that
The diagonal of a rectangular poster board is given by the Pythagorean Theorem
[tex]D^2=L^2+W^2[/tex]
where
D is the diagonal
L is the length
W is the width
we have
[tex]L=28\ in\\D=35\ in[/tex]
substitute the given values
[tex]35^2=28^2+W^2[/tex]
[tex]W^2=35^2-28^2[/tex]
[tex]W^2=441[/tex]
[tex]W=\sqrt{441}=21\ in[/tex]
