I gave you 2 nonexistent triangles to solve, and for obvious reasons you didn't come up with the answer.
Here's another triangle, real acute triange, with the sides: a=7, b=8 and c=9. Find the area(A).
s = [7 + 8 + 9] /2 = 24/2 = 12
And using Heron's formula, we have
A = √[12 * (12-7) * (12 - 8) * (12 - 9)] =
√[12 * 5 * 4 * 3] =
√[12 * 5 * 12] =
√[144 * 5 ] =
12√5 sq units
