Question

answer.......plz urgent

Answer 1

Hi Preeti !
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Area of equilateral  triangle = √3xa²/4 = 64√3/25 
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then ,

√3xa²/4 = 64√3/25 

a²/4      = 64/25 

a²         = 64 x 4 / 25 

a²         = 8 x 8 x 2 x 2 / 5 x 5 

√a²       =√(8 x 8 x 2 x 2 / 5 x 5 )

a          = 8 x 2 / 5 

a          = 16/5 cm or = 3.2 cm

Perimeter = 3 x side = 3 x 16/5 = 48/5 cm  or 9.6cm

also area of triangle - 1/2 x b x h = 64√3/25 

1/2 x 16/5 x h = 64√3/25 

16/5 x h           = 64 x 2 x √3 / 25 

h                      = 4 x 2 x √3 / 5

h                      = 8√3/5  or 2.77cm