Question

' △ABC and △DEF are equilateral triangles. If A(△ABC ):A( △DEF ) =1:2 and AB=4,findDE. ​

Answer 1

A ( ABC)/A (DEF)=(AB)^2/(DE)^2

1/2=(4)^2 /(DE)^2

1/2=16/DE^2

DE^2 =16×2

DE^2 =32

DE =under root 16 ×2

DE = 4under root 2

IT IS THE ANSWER.

Answer 2

Triangle ABC and Triangle DEF are equilateral triangles.

As we know that all equilateral triangles are similar.

By similar triangle theorem ,. Ar(∆ABC)/Are(∆DEF)=AB²/DE²

1/2=4²/DE²

1/2=16/DE²

32=DE²

√32=DE

DE=4√2

HOPE IT HELP YOU.