Calculating TV width/height, based on diagonal length?

Widescreen (16:9) and 4:3 TVs will have a different formula. The manufacturers cheat and tell you the diagonal length, to make the number look bigger, but how do you figure out the width/height with the diagonal length?

That should get added to the list of conversions.

[JohnS]

Originally Posted by Unregistered

Widescreen (16:9) and 4:3 TVs will have a different formula. The manufacturers cheat and tell you the diagonal length, to make the number look bigger, but how do you figure out the width/height with the diagonal length?

That should get added to the list of conversions.

For a 4:3 tv, the height:width:diagonal are in the ratio 3:4:5. So the height is 3/5 x the diagonal, and width 4/5
(or 60% and 80%).

For a 16:9 tv, the ratio is 9:16:sqrt(337). Height is 9*diag/sqrt(337), width is 16*diag/sqrt(337), or about 49% and 87% of diagonal.

nice work thanks

diagonal is 25, height is 15, width?

[JohnS]

Originally Posted by Unregistered

diagonal is 25, height is 15, width?

20" as explained in post 2.

nice job, finally i got it, but honestly the 16:9 not so much, i guess i can find the % given but i want to know how u derive at the % , if u don't mind
tks

[JohnS]

The diagonal squared is equal to the sum of the sides squared. From the 16:9 ratio, I computed the diagonal, and refigured each side to the diagonal as a ratio. If the sides are 9 and 16, the diagonal is sqrt(337) = 18.3576

This is pythagorean theorem: The sum of the sides squared is equal to the diagonal squared

You take both sides 3 and 4 and use arctan to get the angles that are not 90deg. Repeat the process with the 16 and 9. Then use the law of sines to get that the W*0.85=SD. Where W is the widescreen diagonal and SD is the 3:4 diagonal measurement.

My teacher gave me a worksheet that says ''Going to the mtric lengths''.And im on number 2 it says what is the height of the tv.i have no idea and it doesnt tell us what kind of tv it is.im really confused on it.who can help me on this!!!!!