Question 32
The base $AB$ of a triangular piece of paper $ABC$ is $16\,\mathrm{cm}$ long. The paper is folded down over the base, with the crease $DE$ parallel to the base, as shown. The area of the triangle projecting below the base (shaded region) is $16\%$ of the area of $ABC$. What is the length of $DE$, in $\mathrm{cm}$?
