ΔABC ~ ΔDEF and the perimeters of ΔABC and ΔDEF are 30 cm and 18 cm respectively. If BC = 9 cm then EF = ?
Since the 
ABC ∼ 
DEF
Their sides will be same ratios. Let the ratio be K
= 
= 
= K………….1
AB + BC + AC = K (DE + EF + DF)
= K
1.67 = k
From…… 1
= 1.67
EF = 5.4 cm
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