Question

problem: 1
a certain television is advertised as a 90 - inch tv (the diagonal length). if the height of the tv is 63 inches, how wide is the tv? round to the nearest tenth of an inch.

Explanation:

Step1: Apply Pythagorean theorem

Let the width be $w$, height $h = 63$ inches and diagonal $d=90$ inches. By the Pythagorean theorem $d^{2}=h^{2}+w^{2}$, so $w^{2}=d^{2}-h^{2}$.

Step2: Substitute values

$w^{2}=90^{2}-63^{2}=8100 - 3969=4131$.

Step3: Solve for $w$

$w=\sqrt{4131}\approx64.3$ inches.

Answer:

$64.3$ inches