Question

The semi-perimeter of an equilateral triangle is 9 cm, and then its area is ____cm².​

Answer 1

Answer:

35.07 cm

Step-by-step explanation:

Answer 2

Answer:

area is  9√3 cm²

Step-by-step explanation:

Let the side of equilateral triangle = x cm

semi perimeter , s = 9 cm

3x/2 = 9

x = 18/3 = 6 cm

∴ area of an equilateral triangle , = √3/4 × side²

= √3/4 × (6)²

=  9√3 cm²