Answer
$x = 34.2$ ft.
Work Step by Step
Since we have the measure of one angle and the measure of the hypotenuse, we can use the sine ratio to find $x$, which is the side opposite to the angle.
The sine ratio is given as follows:
sin $A = \frac{opposite}{hypotenuse}$
Let's plug in what we know:
sin $20^{\circ} = \frac{x}{100}$
Multiply each side by $100$:
sin $20^{\circ}(100) = x$
Multiply to solve:
$x = 34.2$ ft.
