Answer:
![DE=18.38](https://tex.z-dn.net/?f=DE%3D18.38)
Step-by-step explanation:
It is given that the length of triangle base is 26 that is BC=26.
A line, which is parallel to the base divides the triangle into two equal area parts.
Therefore, from the given information,
.
Now, since it is given that A line, which is parallel to the base divides the triangle into two equal area parts, thus
![\frac{ar ADE}{arABC}=\frac{1}{2}=\frac{(DE)^{2}}{(BC)^{2}}](https://tex.z-dn.net/?f=%5Cfrac%7Bar%20ADE%7D%7BarABC%7D%3D%5Cfrac%7B1%7D%7B2%7D%3D%5Cfrac%7B%28DE%29%5E%7B2%7D%7D%7B%28BC%29%5E%7B2%7D%7D)
⇒![\frac{(DE)^{2}}{(BC)^{2}}=\frac{1}{2}](https://tex.z-dn.net/?f=%5Cfrac%7B%28DE%29%5E%7B2%7D%7D%7B%28BC%29%5E%7B2%7D%7D%3D%5Cfrac%7B1%7D%7B2%7D)
⇒![\frac{(DE)^{2}}{(26)^{2}}=\frac{1}{2}](https://tex.z-dn.net/?f=%5Cfrac%7B%28DE%29%5E%7B2%7D%7D%7B%2826%29%5E%7B2%7D%7D%3D%5Cfrac%7B1%7D%7B2%7D)
⇒![(DE)^{2}=13{\times}26=338](https://tex.z-dn.net/?f=%28DE%29%5E%7B2%7D%3D13%7B%5Ctimes%7D26%3D338)
⇒![DE=18.38](https://tex.z-dn.net/?f=DE%3D18.38)