If the three sides of a triangle are 11 cm, 12 cm and 13 cm, then wha…

We know that,

Area of a triangle = \(\sqrt {s(s-a)(s-b)(s-c) }\)

and semi perimeter = \(\frac{a + b + c}{2}\)

The three sides of a triangle are 11 cm, 12 cm and 13 cm,

So according to the question,

semi perimeter = \(\frac{11 + 12 + 13}{2}\) = 18cm

Area of triangle = \(\sqrt {18(18-11)(18-12)(18-13) }\)

= \(\sqrt {18(7)(6)(5) }\)

= \(\sqrt {18(210) }\)

= \(\sqrt {3780 }\) = $6\sqrt{105}$