Solution:
In 
Thus, by using Basic Proportionality Theorem, we get,
![\[\therefore \mathrm{BD} / \mathrm{DA}=\mathrm{BE} / \mathrm{EC}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-846ad07206e698b454f5111b21a08b79_l3.png "Rendered by QuickLaTeX.com")
In 
Thus, by using Basic Proportionality Theorem, we get,
![\[\therefore \mathrm{BD} / \mathrm{DA}=\mathrm{BF} / \mathrm{FE}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-4125825dde82c5cce57ebbf451d22bd3_l3.png "Rendered by QuickLaTeX.com")
From equation (i) and (ii), we get
Hence, proved.
In the figure, DE 
