Question

1) triangle ABC similar to TriangleDEF Bc=3cm, Ef=4 and
area of TRIANGLEABC = 45 cm². Find the area of triangleDEF​

Answer 1

Answer:

Step-by-step explanation:

Hi ,

Area ∆ABC = 45 cm²,

BC= 3 cm , EF = 4 cm

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We know that,

If ∆ABC ~ ∆DEF then ,

( ar∆ABC ) / ( ar∆DEF ) = BC²/ EF²

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45 / ∆DEF = 3²/4²

= 9/16

∆ DEF = ( 45 × 16 ) / 9

= 80 cm²

I hope this helps.

Answer 2

$\bold{\huge{\fbox{\color{Violet}{Solution}}}}$

According to theorem :-

The ratio of areas of two similar triangles are equal to their ratios of corresponding sides.

So,

==> ar(ΔABC) / ar(ΔDEF = BC^2/EF^2

==> 45/ar(ΔDEF) = 3^2/4^2

==> ar(ΔDEF) = (45 × 16)/9 = 720/9 = 80cm^2

So,

==> ar(ΔDEF) = 80cm^2