Many television screens are rectangles that are measured by the length of their diagonals. The ratio of the horizontal length to the height in a standard television screen is $4:3$. What is the horizontal length (in inches) of a ``27-inch'' television screen?
Take a look at this: https://artofproblemsolving.com/wiki/index.php/2003_AMC_10B_Problems/Problem_6
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