Question

Find the area of an equilateral triangle whose perimeter is 18 cm.​

Answer 1

3a=18

a=6

s=a+b+c/2

=18/2

=9

ar=√s(s-a)(s-b)(s-c)

ar=√9(9-6)(9-6)(9-6)

ar=√9•3•3•3

ar=9√3cm^2

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Answer 2

Answer:

Perimeter of equilateral triangle=sum of all sides

18=3{side}

18÷3=side

Side=6

Then,area of equilateral triangle=√3/4(side×side)

Area=9√4

Step-by-step explanation:

If u don't understand look the picture

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