Question

find the length x.

Explanation:

Step1: Use similar - triangles property

Since the two right - angled triangles are similar, the ratios of their corresponding sides are equal. We have the proportion $\frac{3.5}{x}=\frac{7}{8}$.

Step2: Cross - multiply

Cross - multiplying the proportion gives us $7x = 3.5\times8$.

Step3: Solve for x

First, calculate $3.5\times8 = 28$. Then, $x=\frac{28}{7}=4$.

Answer:

$4$