A certain television is advertised as a 90- inch Tv ( the diagonal length).

Answer:
The width is 64.3 inches
Step-by-step explanation:
Given
[tex]d = 90[/tex] --- diagonal
[tex]h = 63[/tex] --- height
Required
Determine the width (w) of the TV
To do this, we make use of Pythagoras theorem which is illustrated as:
[tex]d^2 = h^2 + w^2[/tex]
So, we have:
[tex]90^2 = 63^2 + w^2[/tex]
Evaluate all squares
[tex]8100 = 3969 + w^2[/tex]
Collect like terms
[tex]w^2 = 8100 - 3969[/tex]
[tex]w^2 = 4131[/tex]
Take positive square roots of both sides
[tex]w = \sqrt{4131[/tex]
[tex]w = 64.3[/tex] -- approximated