Question

find the area of a equilateral trisangle whose perimeter is 18 cm​

Answer 1

Answer:

Step-by-step explanation:

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