Q9 of 32 Page 6

In Fig. 6.19, DE || AC and DF || AE. Prove that


(CBSE 2005, 2007)


 


Given: In triangle ABC, DE is parallel to AC

Basic Proportionality Theorem: If a line is parallel to a side of a triangle which intersects the other sides
into two distinct points, then the line divides those sides in proportion.

Therefore,

By Basic proportionality theorem

    ......(1)

In triangle BAE, DF is parallel to AE


Therefore,

By Basic proportionality theorem

   ...... (2)

From (1) and (2), we get


Hence, Proved.

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