Answer
$x = 18.7$
Work Step by Step
Since we have the measure of one angle and the measure of the side opposite to that angle, we can use the sine ratio to find $x$, which is the hypotenuse of the triangle.
The sine ratio is given as follows:
sin $A = \frac{opposite}{hypotenuse}$
Let's plug in what we know:
sin $40^{\circ} = \frac{12}{x}$
Multiply each side by $x$:
sin $40^{\circ}(x) = 12$
Divide both sides by sin $40^{\circ}$ to solve for $x$:
$x = 18.7$
