Q5 of 65 Page 128

In Fig. 6.20, DE || OQ and DF || OR. Show thatEF || QR.

Given that In triangle POQ, DE parallel to OQ

Hence,


(Basic proportionality theorem) (i)


Now,



Hence,


(Basic proportionality theorem) (ii)


From (i) and (ii), we get



Therefore,


EF is parallel to QR (Converse of basic proportionality theorem)


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