The dagonal of the television is the distance between the opposite vertices of the television. A right angle triangle would be formed as shown below
We would solve for the diagonal, d by applying pythagorean theorem which is expreesed as
![\begin{gathered} \text{hypotenuse}^2=oppositeside^2+adjacentside^2 \\ \text{hypotenuse = d} \\ \text{opposite side = 30} \\ \text{adjacent side = 40} \\ d^2=30^2+40^2\text{ = 900 + 1600 = 2500} \\ d\text{ = }\sqrt[]{2500} \\ d\text{ = 50} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/r4v408y12o0ya45il16sacclaevd1fg0kw.png)
The length of the diagonal is 50 inches