Question 21529
Use Heron's formula to find the area of your triangular yard.

{{{A = sqrt(S(S-a)(S-b)(S-c))}}} where: S = semi-perimeter of the triangle S=190 ft) and a, b, & c are the lengths of the sides of the triangle.

{{{A = sqrt(190(190-110)(190-120)(190-150))}}}
{{{A = sqrt(190(80)(70)(40))}}}
{{{A = sqrt(4256000)}}}
{{{A = 6523.8}}}square feet. Divide this by 1200 sq.ft. per bag.
{{{6523.8/1200 = 5.4}}}

You will need 6 bags of fertilizer