Question

answers....... for q.3

Answer 1

this question can be solved by a property which is given in your chapter

Answer 2

Solution :

It is given that ,

∆ABC ~ ∆DEF ,

ar( ∆ABC ) = 169 cm² = ( 13 cm )²

ar( ∆DEF ) = 121 cm² = ( 11 cm )²

AB = 20 cm

Now ,

we know that ,

If ∆ABC ~ ∆DEF, then

AB²/DE² = [ ar(∆ABC)]/[ar(∆DEF)]



=> 20²/DE² = ( 13 cm )²/( 11 cm )²

=> 20/DE = 13/11

=> DE/20 = 11/13

=> DE = ( 11 × 20 )/13

=> DE = 220/13

DE ≈ 16.92 cm

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