Precalculus, Chapter 6, 6.2, Section 6.2, Problem 37

Given: a=8, b=12, c=17
Heron's Area Formula A=sqrt[s(s-a)(s-b)(s-c)]
where s=[a+b+c]/2
s=[8+12+17]/2=37/2=18.5
A=sqrt[18.5(18.5-8)(18.5-12)(18.5-17)]
A=sqrt[18.5(10.5)(6.5)(1.5)]
A=sqrt(1893.94)=43.52
The area is 43.52 square units.