Mathematics: How does one calculate a television's height and width based on its diagonal length and aspect ratio?

TV screens are flat rectangular shapes, and when we cut it diagonally, in effect we are having two equivalent right angle triangles.

So we have diagonal length as , whose value is say 36".

Aspect ratio is the ratio between height and width in effect  say it is something like 16:9.

So in effect



.

X here is unknown variable that would give us the actual width and height.

So here we have a right angled triangle with the longest side  and the other two sides being 

So for a right angle triangle we apply the Pythagoras theorem here, and that would mean



Now taking x to one side




Once we find value of X, that would give us the actual height and width.
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