this is some tough stuff, and I had to mull over some trigonometry formulas
Using Heron's formula, you can find the area of a triangle, knowing only it's 3 side lengths
the pythagorean theorum goes heavily into this as well, if we seperate each of the triangles and solve each one for the pythagoean, we will slowly but surely be able to get the altitude (height) and then solve for the area
basically, The formula is
16A²=4a²*b²-(a²+b²-c²)²
but since algebra was surprisingly not invented way back when, they made a formula surprisingly simplified
Area=√(a+b+c/2)(a+b-c/2)(a-b+c/2)(-a+b+c/2)
so here we go,
lets assign each value
a=7
b=18
c=14
now we plug into the formula
Area=(7+18+14)(7+18-14)(7-18+14)(-7+18+14)
Area=(39)(11)(3)(25)
(divide the sum of each value in each parenthesis by 2)
Area=(19.5)(5.5)(1.5)(12.5)
multiply all the numbers together
Area= 2010.9375 cm sq