How do I calculate the screen dimensions of a HDTV? I know the diagonal and the ratio of the sides. My algebra is very rusty.

You need to find the angle by taking the arctangent of the ratio of the vertical height divided by the horizontal width.

Using this angle and the length of the diagonal, you use the sin and cos functions to find how long the sides are.

I would use a ruler.


Edit: an HD ruler



Edited 1 time(s). Last edit at 03/28/2008 06:58PM by papercup.

Playing off of freeradicals way....


16:9...(goes to car to get TI calculator...)

arctan(9/16)=34.22 degrees.

Lets say your TV is 42 inches....
42cos(34.22)=34.729: width
42sin(34.22)=23.61: height.

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Guess?

I like microchip's way, but this site disagrees with the result:

[www.cavecreations.com]

For a 42" HDTV--36.6 x 20.6 inches

No math needed - check the product sheet on the HDTV you want to buy. It will list the dimensions of the TV and the screen.

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Article Accelerator
I like microchip's way, but this site disagrees with the result:

[www.cavecreations.com]

For a 42" HDTV--36.6 x 20.6 inches

Yeah, the angle is really 29.36 degrees.

I had to call a physicist friend. Here is the answer:
d = diameter, h = height, w = width

d^2 = w^2 + h^2

the ratio of width to height is 16 to 9

d^2 = (16/9 h)^2 + h^2

d^2 = 4.16h^2

d = 2.04h

So for a 32" screen the height is about 16"

Here's where I get my info on screen sizes/dimensions. And the chart also lets you relate 4:3 screens to 16:9 screen sizes. Great for figuring out what size widescreen you need to get to compare with a 4:3 screen. I'm no good at math, anyway :-(

[www.cavecreations.com]

LyleH

Product Spec sheets . . . anything else is simply guessing. Screen size is NOT the size of the TV, so if you are trying to fill a specific space, GFL . . .

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Bill
Flagler Beach, FL 32136

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Forrest
No math needed - check the product sheet on the HDTV you want to buy. It will list the dimensions of the TV and the screen.

Damn mind reading, joke stealing plagiarist forum puke!

Check the spec sheets, or measure a screen with a ruler.

Jebb, my algebra is awful but shouldn't d = diagonal? What does diameter have to do with anything?

P.S.: My geometry is awful too.

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I think that's what Jebb's physicist friend means. The physicist appears to be channelling an ancient Greek philosopher...

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Forrest
No math needed - check the product sheet on the HDTV you want to buy. It will list the dimensions of the TV and the screen.

I assume that the OP wants to figure out what the minimum size HDTV is that they need to replace their current TV. There's a chart that shows what size(s) of HDTV you need to get the same size (e.g. "height" picture as a 4:3 TV here (I'd try to cut and paste but it looses the table layout) :

Replacement Sizes for replacing 4:3 TV with HDTVs

Must be a slow day - this message is 9 months old!