Question

A signboard is in the shape of equilateral triangle with side a. find the area of the signboard using heron's formula. if the perimeter of the board is 210cm. what will be it's area
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Answer 1

Answer:

given side of an equilateral triangle = a

perimeter of an equilateral traingle = 210cm

=> 3a = 210

=> a = 210/3 = 70 cm

heron's formula = √ [ s(s - a)(s-b)( s-c) ]

where s is semiperimeter which is equal to a+b+c/2

= 70+70+70/2 = 105cm

area of Δ = √[ 105(105-70)(105-70)(105-70)]

= √[ 105( 42875) ] = 1225√3 sq.cm

hope it helps u !!!!