Answer:
3.9msquare inches(round to 1dp)
Explanation:
herons formula can be used to calculate the area of any triangle
and the triangle you mentioned is an equilateral one
the formula is A=√(s(s-a)(s-b)(s-c)) where √ means square root and abc are the sides of the triangle and s is the semi perimeter of the triangle such that a+b+c/2=s and A is the area of the triangle so,
3+3+3
=9/2
=4.5=s
√(4.5(4.5-3)(4.5-3)(4.5-3)
=√15.1875
=3.9 square inches (round to 1dp)