Question

if ∆ABC~∆DEF and AB=3DE with ar (∆ABC)=144cm², find ar(∆DEF).

Answer 1

ar(ABC)/ar(DEF)=ABsquare /DEsquare
144/ar(DEF)=(3 DE)square/ DEsquare
ar(DEF)=144*9 DEsquare / DEsquare
ar(DEF)=16cm Sq.