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. The ratio of the vertical sides is equal to the ratio of the horizontal sides. So, $\frac{x}{5}=\frac{4}{8}$.

Step2: Solve for x

Cross - multiply the equation $\frac{x}{5}=\frac{4}{8}$ to get $8x = 4\times5$. Then $8x=20$, and $x=\frac{20}{8}=\frac{5}{2}=2.5$.

Answer:

$2.5$