How to find the dimensions of a screen?

blackbox_dev · Post by **blackbox_dev** » Wed Jan 10, 2007 8:40 pm

I want to buy a 2.5" LCD screen, but need to know the dimensions of the panel first. Most likely (it's not actually stated, but I know it's not widescreen), the screen is a 4:3 ratio, and I know that vertically the panel is 1 9/16". How do I find the dimensions vertically?

ATOMICMAN · Post by **ATOMICMAN** » Wed Jan 10, 2007 8:50 pm

using algebra then? the pythagorean theorem?

a^2 + b^2 = c^2 ?

1.95" or so is the horizontal then

Post by **Skyone** » Wed Jan 10, 2007 9:23 pm

ATOMICMAN wrote:using algebra then? the pythagorean theorem?

a^2 + b^2 = c^2 ?

1.95" or so is the horizontal then

Because most panels are square triangles in shape, right?

1.5625" * 1.33.. = 2.0833..."

1.5625" x 2.083"

daguuy · Post by **daguuy** » Wed Jan 10, 2007 9:28 pm

5" screens are 4"x3" and 2.5" screens are half that size and the same aspect ration so they're 2" x 1.5"

Post by **Skyone** » Wed Jan 10, 2007 10:19 pm

Oh, the PANEL is 1 9/16"? The viewable screen should be 2" x 1.5" then, like daguuy said. With the metal border around the view, it should be ~2 1/4" by ~1 7/8"

jperryss · Post by **jperryss** » Thu Jan 11, 2007 9:30 am

Ya know, I was ready to laugh at the Pythagorean Theorem guy like the rest of you, but he was right.

We know the diagonal of the screen is 2.5". We also know that the height is 1 9/16", which is 1.562". The Pythagorean Theorem says a^2 + b^2 = c^2.

We know if we cut the screen in half from top right to bottom left, we have a right triangle, correct? So we have the A and the C, let's determine the B.

a^2 + b^2 = c^2
1.562^2 + b^2 = 2.5^2
2.4398 + b^2 = 6.25
b^2 = 6.25 - 2.4398
b^2 = 3.81
b = 1.952" (just about 2", would probably be 2 if I carried over more decimal points)

See folks, there's a little bit of math in each and every show.