A certain television is advertised as a 50 -inch TV(the diagonal length). If the width...

Let l be the length of the TV, in inches. Since the diagonal of the TV forms a right triangle with the length and width (legs), the Pythagorean Theorem can then be used to determine l:
${\displaystyle l^2+{14}^2={50}^2}$
${\displaystyle l^2+196=2500}$
${\displaystyle l^2=2304}$
${\displaystyle l=\sqrt{2304}}$
$l=48$
Consequently, the TV is 48 inches long.