In an older television set, the screen height is 0.75 times the screen width.

If a television set measures 20 inches along the diagonal, what is the screen width?

The television set has a rectangular shape. The diagonal of this rectangle along with its width and length together form a right angular triangle.

This means that we can apply the Pythagorean theorem which states that:

(diagonal) ^2 = (length) ^2 + (width) ^2

Let the width be w. We know that the length is 0.75 times the width, this means that: length = 0.75 w

Substitute in the above equation:

(20) ^2 = (0.75w) ^2 + (w) ^2

400 = 0.5625 w^2 + w^2

400 = 1.5625 w^2

w^2 = 256

w = 16

This means that the width of the screen is 16 in.