Question

find the length x.

Explanation:

Step1: Use similar - triangle property

Since the two triangles are similar, the ratios of their corresponding sides are equal. That is, $\frac{x}{6}=\frac{3.5}{3}$.

Step2: Solve for x

Cross - multiply to get $3x = 6\times3.5$. Then $3x=21$, and $x = 7$.

Answer:

$7$