Question

In a standard television set, the screen height is 0.75 times the screen width. If a television set measures 34 inches along the diagonal, what is the screen width?

Answer 1

We can solve this by using the  Pythagorean theorem which is below:

$a^2 + b^2 = c^2$

Or we can say
$w^2 + h^2 = d^2$
w = widht
h = height
d = diagonal measure


With that said, we know the height is .75 times the width so .75w. We also know d = 34, which is our diagonal measure.
w = don't know yet but need to find
h = .75w
d = 34
Now lets plugin the information we know into our equation

$w^2 + h^2 = d^2$
$w^2 + (.75w)^2 = 34^2$
Now lets to the math
$w^2 + (.75w)^2 = 34^2$
$w^2 + (.75w)^2 = 1156$
$w^2 + .5625w^2 = 1156$
Combine like terms
$w^2 + .5625w^2 = 1156$
$1.5625w^2 = 1156$
Divide both sides of the equal sign by 1.5625
$\frac{1.5625w^2}{1.5625} = \frac{1156}{1.5625}$
$w^2 = 739.84$
Now take the square root on both sides of the equal sign
$\sqrt{w^2} = \sqrt{739.84}$
$w = 27.2$

So the width is 27.2
We can check this by putting 27.2 back into our original equation
$w^2 + (.75w)^2 = 34^2$
$27.2^2 + (.75\times 27.2)^2 = 34^2$