Answer
According to the side-splitter theorem, if a line is parallel to a side of a triangle and intersects the other two sides, then those two sides are divided proportionately. This means that the two triangles pictured are similar to one another.
$x = 10$
Work Step by Step
According to the side-splitter theorem, if a line is parallel to a side of a triangle and intersects the other two sides, then those two sides are divided proportionately. This means that the two triangles pictured are similar to one another.
Let's set up a proportion for the sides whose values are given in the figure:
$\frac{x}{14} = \frac{20}{28}$
Use the cross products property to get rid of the fractions:
$28x = 280$
Divide each side of the equation by $28$ to solve for $x$:
$x = 10$