Question

let ∆ABC~∆DEF and their areas be respectively 64cm square and 121cm square..if ef =15.4 cm..find bc

Answer 1

Hope this will helped you a lot

Answer 2

Answer:

BC = 11.2 cm

Explanation:

Given ∆ABC ~∆DEF

and

Area(∆ABC)= A1 =64 cm²

Area (∆DEF)=A2= 121 cm²

EF = 15.4cm , BC =?

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By Theorem:

The ratio of the areas of the

similar triangles is equal to the

ratio of the squares of their corresponding sides .

_________________________

Here ,

$\frac{BC^{2}}{EF^{2}}</p><p>= \frac{A_{1}}{A_{2}}$

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

$\implies \frac{BC^{2}}{(15.4)^{2}}=\left(\frac{8}{11}\right)^{2}$

$\implies \frac{BC}{15.4}=\frac{8}{11}$

$\implies BC = \frac{15.4\times 8}{11}$

$\implies BC = 1.4\times 8$

$\implies BC = 11.2 cm$

Therefore,

BC = 11.2 cm

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