A computer monitor is 20 inches wide. The aspect ratio is 16:9. What is the length of the diagonal of the screen to the nearest whole inch?

whosmans Mar 23, 2018

#1**+2 **

The aspect ratio of a computer monitor is given as width : height. So....

width : height = 16 :9

We are given that the width is 20 inches

Let the height be h inches.

20 inches : h inches = 16 : 9

20 : h = 16 : 9

This means the same as..

20 / h = 16 / 9

Multiply both sides of the equation by h .

20 = h * 16/9

Multiply both sides of the equation by 9/16 .

20 * 9/16 = h

11.25 = h

Now we can use the Pythagorean Theorem to find the length of the diagonal.

(width)^{2} + (height)^{2} = (length of diagonal)^{2}

20^{2} + 11.25^{2} = (length of diagonal)^{2}

400 + 126.5625 = (length of diagonal)^{2}

526.5625 = (length of diagonal)^{2}

√526.5625 = length of diagonal

length of diagonal ≈ 23 inches

hectictar Mar 23, 2018

#1**+2 **

Best Answer

The aspect ratio of a computer monitor is given as width : height. So....

width : height = 16 :9

We are given that the width is 20 inches

Let the height be h inches.

20 inches : h inches = 16 : 9

20 : h = 16 : 9

This means the same as..

20 / h = 16 / 9

Multiply both sides of the equation by h .

20 = h * 16/9

Multiply both sides of the equation by 9/16 .

20 * 9/16 = h

11.25 = h

Now we can use the Pythagorean Theorem to find the length of the diagonal.

(width)^{2} + (height)^{2} = (length of diagonal)^{2}

20^{2} + 11.25^{2} = (length of diagonal)^{2}

400 + 126.5625 = (length of diagonal)^{2}

526.5625 = (length of diagonal)^{2}

√526.5625 = length of diagonal

length of diagonal ≈ 23 inches

hectictar Mar 23, 2018