Question

if ∆ABC ~ ∆DEF and EF = 1/3 BC , then ar(∆ABC) : ar(∆ABC) ar(∆DEF) is ???​

Answer 1

Answer:

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Step-by-step explanation:

Ar ABC : Ar DEF = 9 : 25

since , triangle ABC is similar to triangle DEF , therefore side BC will be similar to Side EF

BC : EF = √9 : √25 => BC : EF = 3 : 5

let constant ratio be "x" then

BC = 3x , EF = 5x

given , BC = 21 cm

3x = 21 => x = 7

EF = 5x = 5 × 7 = 35cm Answer