Herons Formula:
Area of triangle with a,b,c as sides and s=a+b+c2
A=√s(s−a)(s−b)(s−c) .
where, a,b,c are three sides of the triangles and s is semi-perimeter.
For triangle with sides 10 cm, 24 cm and 26 cm,
s=10+24+262=30
=√(6×6)×(5×5)×(4×4)