Mar 16 2005

## How Big Is A 24″ Widescreen?

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Yesterday, my co-worker Damien just about convinced himself to buy two 24″ Widscreen Dell monitors. Before he bought them he wanted to know just how big they would be so what better way to find out than to make a paper mock-up. In the first attempt he took two sheets of A4 paper and lined them up so that the diagonal dimension was 24″. The trouble with this approach is that it is very difficult to get the aspect ratio right and its also ver difficult to acurately measure a 24″ diagonal line with a 12″ ruler.

Enter GSCE maths (I knew I didn’t bunk those lessons for a reason!). We know that the diagonal dimension on the monitor is 24″ so we can use simple trigonometry to work out the lengths of the sides:
[mathml]z^2 = x^2 + y^2[/mathml]
Therefore:
[mathml]x^2 + y^2 = 24^2[/mathml]
[mathml]x^2 + y^2 = 576[/mathml]

We also know that the aspect ratio of the monitor is 10:16 (height:width) so we can workout the component parts of [mathml]x^2 + y^2[/mathml] which gives us:
[mathml]x^2 = 354.5[/mathml]

[mathml]y^2 = 221.5[/mathml]

So we can now workout what the actual dimensions of x (width) and y (height) are:
[mathml]x = sqrt354.5 = 18.8″[/mathml]

[mathml]y = sqrt221.5 = 14.9″[/mathml]

With this knowledge Damien was able to make an acturate replica of the Dell monitor from paper. You can just about see the 17″ Benq monitor behind as a comparisson

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