If you know a wide screen tv (16:9) is 42 inches across the diagonal, how do you compute the length & height?

Answer 1

The 16:9 is the ratio of the sides. So one side is x high, and the other is 16x/9 long.

The 42 is the hypoteneuse of a right triangle with sides x and 16x/9, so just plug-n-chug:

x² + (16x/9) ² = 42 ²

x² + 256x ² / 81 = 1764

81x² + 256x ² = 142,884

337x ² = 142,884

x ² = 142,884 ÷ 337

x = √ (142,884 ÷ 337) = height ≈ 20.6 in.

width = (16/9) * √ (142,884 ÷ 337) ≈ 36.6 in.

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Answer 2

If the TV is (16:9) that means the ratio of the sides is 4 to 3...By pythagoras theorem, the length of the diagonal is the root of the sum of 4 squared and 3 squared which gives 5. if 42 inches is proportional to 5, the height and length are proportional to 42 keeping the ratio intact. hence the height is (42/5)*3 and the length is (42/5)*4 which gives 25.2 and 33.6 respectively. Of course in actual fact its more than that because of packing and the panels you see but theoretically, these are the height and length dimension!! cheerio!!

Answer 3

Hi. 42" is the hypotenuse of a right triangle. Knowing the ratio (16:9) of the triangle, just plug in the values. Hint: 1:1.777...

Answer 4

You don't have to ..that is how you measure the TV screen diagonally .