We know that, the radius of a circle inscribed in a equilateral triangle = a/[2?3]Where, a be the length of the side of an equilateral triangle.Given that, area of a circle inscribed in an equilateral tringle = 154 cm2? ?(a/2?3)2 = 154? (a/2?3)2 = 154 x (7/22) = (7)a2? a = 42?3 cmPerimeter of an equilateral triangle = 3a = 3(14?3) = 42?3 cm