Answer: we would need 7 bags of fertilizer to cover the area of the triangle.
Explanation:
To find the area of a triangle, we can use Heron's formula. Heron's formula states that the area of a triangle can be found by taking the square root of the semi-perimeter multiplied by the difference of the semi-perimeter and each side length.
The semi-perimeter of the triangle is (2.1+1.8+2.7)/2 = 2.7
The area of the triangle is sqrt(2.7*(2.7-2.1)(2.7-1.8)(2.7-2.7)) = sqrt(2.70.60.9*0) = 1.35
Each bag of fertilizer covers 0.2 square miles, so we need to divide the area of the triangle by the area covered by each bag to find how many bags are needed: 1.35 / 0.2 = 6.75
Rounding up to the nearest whole number, we would need 7 bags of fertilizer to cover the area of the triangle.