The area of an equilateral triangle is cm2. Its height is-
It is given in the question that,
Area of an equilateral triangle = 81 cm2
Let a be the side of the triangle and h be the height
We know that,
Area of an equilateral triangle =
81 =
a2 = 81 × 4
a = 18
Also, Area of triangle =
81
h =
h = 9 cm
Hence, option (a) is correct