20X2=40marks

Let the height of the LCD is x''

∴The width is 16/9 x''

x2+(16/9 x)2=192 (Pyth.theorem)

x2+256/81 x2=192

337/92 x2=192

x2=192/337*92

x=√(192*92/337)

x=19*9/√337

x=171/√337

∴The height is (171/√337)''

∴The width is (16/9 * 171/√337)''=(304/√337)''

∴The size is (304/√337)'' * (171/√337)'' = (304*171/337)inch2 = 154inch2 (corr. to 3 sig. fig.)



If I keep the same height, but change it to 4:3

The size is = width*height

=4/3*height*height

=4/3*(171/√337)2inch2

=(4*1712)/(3*337)inch2

=(4*1712)/(3*337)inch2

=116inch2 (corr. to 3 sig. fig.)

if i have a lcd is 19",it is16:9
what is the size of it?(x times x)
LCD is 19", that means the diagonal is 19".
(16a)2 + (9a)2 = 192
337 a2 = 361
a = √(361/337) = 1.035
Hence width of LCD is 16 x 1.035 = 16.56 inch
and height of LCD is 9 x 1.035 = 9.315 inch
size of a 19" 16:9 LCD is 16.56 inch times 9.315 inch

If the height is kept at 9.315 inch,
width = 9.315 /3 * 4 = 12.42 inch
Hence, size of a 19" 4:3 LCD is 12.42 inch times 9.315 inch

1. 171
-------
304

2. 57
-----
76