# $$\triangle$$ ABC ~ $$\triangle$$ DEF and their areas are respectively 64 $$cm^2$$ and 121 $$cm^2$$. If EF = 15.4 cm, find BC.

## Solution :

We have,    area of triangle ABC = 64 $$cm^2$$

and area of triangle DEF = 121 $$cm^2$$

We know that,

$$ar(\triangle ABC)\over ar(\triangle DEF)$$ = $$({BC\over EF})^2$$

$$\implies$$  $$64\over 121$$ = $$({BC\over 15.4})^2$$

$$\implies$$ $$8\over 11$$ = $$BC\over 15.4$$

$$\implies$$ BC = 11.2 cm.