$3\mathrm{.}26$ LAB: Area of a triangle Using Heron's formula, you can calculate the area of a triangle if you know the lengths of all three sides. Given the length of each side of a triangle as input, calculate the area of the triangle using Heron's formula as follows: s $=$ half of the triangle's perimeter area $=$ the square root of s$*($s$-$a$)*($s$-$b$)*($s$-$c$),$ where a$,$ b$,$ and c are each sides of the triangle. Hint: Use the math function sqrt$()$ for calculating the square root. Output the floating$-$point value of the area with two digits after the decimal point using the following statement once before all other cout statements: cout $<<$ fixed $<<$ setprecision$(2)$; In c$++$