Let's quickly draw the television screen
We'll focus on the following triangle, in which we can use Pythagoras's theorem to calculate the lenght of the missing side
We know
[tex]hyp^2^{}=b^2+h^2[/tex]
Where b and h are the sides that form the right angle. In this case
[tex]625=b^2+225[/tex][tex]b^2=400[/tex][tex]b=20[/tex]
And so, the width of the screen is 20 inches.
