AVS Forum banner
Status
Not open for further replies.
1 - 6 of 6 Posts

·
Registered
Joined
·
207 Posts
Discussion Starter · #1 ·
Apologies in advance .........


Can someone please tell me what the width and height measurements are for 80, 90 and 100 inch diameter 16:9 screen sizes and also for 2.35:1 80, 90 & 100 inch diameter screens (I only went to school to eat my lunch.....).


Thanks.
 

·
Registered
Joined
·
7,335 Posts
I think you mean Diagonal, not diameter. Most rectangular objects don't have diameters :D


Next, I'm pretty sure those dimensions you gave are common screen widths not diagonals.


You're working with a right triangle here, so the pythagorean theorem is in effect. Assuming you're correct, for a 16:9 screen, the formula is


(16x)^2 + (9x)^2 = (diagonal)^2


256x^2 + 81x^2 = (diagonal)^2.


337x^2 = diagonal^2


Solving for an 80" diagonal, you have

337x^2 = (80)^2


337x^2 = 6400 (just use this formula for 16:9 screens all the time, I'm showing the work)


x^2 = 6400 / 337


x = 4.36"


So you know that the common unit is 4.36"


Width = 16x or 69.76" (basically 70")

Height = 9x or 39.24"


For a 2.35"1 screen, the pythagorean theorem is still in effect,


(2.35x)^2 + (x)^2 = (diagonal)^2

5.5225x^2 + x^2 = (diagonal)^2


Use this then:

6.5225x^2 = (diagonal)^2


Solving for an 80" diagonal, we'd have


6.5525x^2 = 80^2


x^2 = 6400 / 6.5525


x^2 = 976.76 (call it 977)


x = 31.26


Width = 2.35 * 31.26 or 73.46"

Height = 31.26


This checks out correctly :D


If it's width, you just use width/16 (for 16:9 screens) and width / 2.35 (for 2.35:1) screens and solve.


For an 80" width, we have


80/16 = 5, so X = 5.


(16x)^2 + (9x)^2 = diagonal^2

80^2 + 45^2 = diagonal ^2

6400 + 2025 = diagonal^2

8425 = diagonal^2

91.78 = diagonal


For a 2.35:1 screen, x = 34.04


(2.35x34.04)^2 + (34.04)^2 = diagonal^2

(80)^2 + (34.04)^2 = diagonal^2

6400 + 1158.72 = diagonal^2

7558.72 = diagonal^2

86.94 = diagonal


Regards,
 

·
Registered
Joined
·
7,335 Posts
Strahan,


This was a practical application of the work of Pythagorus :D


I know there was a reason I paid attention in Geometry Class.


Regards,
 

·
Registered
Joined
·
207 Posts
Discussion Starter · #5 ·
Thanks John.


I'm working with a limited width (approx. 80") for a screen and seeing if I can work something that would fit above my existing tv and hifi equipment storage unit in a family room situation. Now have to work out throw distances (thinking of coffee table set up. Wife won't let me hang anything from the ceiling....).
 

·
Registered
Joined
·
3 Posts
or simply,


For 16:9 screens:

Width = Diagonal divided by 1.15

Height = Diagonal divided by 2.04


For 2.35:1 screens:

Width = Diagonal divided by 1.087

Height = Diagonal divided by 2.554


For 4:3 screens:

Width = Diagonal divided by 1.25

Height = Diagonal multiplied by 0.6
 
1 - 6 of 6 Posts
Status
Not open for further replies.
Top