Question

find area of triangle whose sides are 8cm,11cm,13cm using herons formulae

Answer 1

Ans is in picture. Open it to see.

Answer 2

$A=\sqrt{s(s-a)(s-b)(s-c)$

$s=\frac{1}{2}a+b+c$
$s=\frac{1}{2}8+11+13$
$s=\frac{1}{2}32$
$s=16$

$A=\sqrt{16(16-8)(16-11)(16-13)}$
$A=\sqrt{16(8)(5)(3)$
$A=\sqrt{1920}$

Ans=$\sqrt{1920}$