



 
We have two responses for you Hi Brian, You haven't stated the units but I assume all three lengths are in the same units. For Heron's Formula I use a, b and c as the side lengths and s as the semi=perimeter, s = (a + b + c)/2. Thus for your example
The area is then given by
where sqrt is the square root. Thus
Penny
Brian, Because the numbers were so large, I divided each number under the square root by 10, thus I divided by 10000^{1/2} = 100 and hence I need to also multiply by 100 A = (830 × 310 × 310 × 210)^{1/2}  


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