Question

The aspect ratio​ (length to​ width) of an lcd computer monitor is 5​ : 4. the lcd monitor of a toshiba laptop computer has a perimeter of 32.4 inches. what is the diagonal measure of the​ screen? round to the nearest tenth of an inch.

Answer 1

Solution:

Formula of perimeter = $2(W+H)$

So, 2W + 2H = 32.4         ... (1)

Ratio = 5:4

So, $\frac{W}{H} =\frac{5}{4}$

4W - 5H = 0         ... (2)

Solve equation (1) and (2).

W = 9.0 and H = 7.2

Use the Pythagorean theorem,

$W^{2} + H^{2} = D^{2}$

$D^{2} = (9.0)^{2} + (7.2)^{2}$

$D^{2} = 132.84$

D = 11.52

D = 11.5

Hence, the measure of diagonal is 11.5 inches.