Question

find the length x.

Explanation:

Step1: Identify similar triangles

The two right - angled triangles are similar. The ratio of their corresponding sides is equal.

Step2: Set up the proportion

The ratio of the vertical sides is the same as the ratio of the hypotenuses. So, $\frac{2}{4}=\frac{3.5}{x}$.

Step3: Cross - multiply

Cross - multiplying gives $2x = 4\times3.5$.

Step4: Solve for x

$2x=14$, then $x=\frac{14}{2}=7$.

Answer:

$7$