Question

The sides of a triangle are $12$cm,$16$cm and $20$cm. Find its area.

Answer 1

Sides of triangle $a=12$cm, $b=16$cm and $c=20$cm

$s=\frac{a+b+c}{2}=\frac{12+16+20}{2}=\frac{48}{2}=24$cm

Using Heron's formula,

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

$=\sqrt{(24-12)(24-16)(24-20)}$

$=\sqrt{\left(12\right)\left(8\right)\left(4\right)}$

$=\sqrt{4\times 3\times 4\times 3\times 4}$

$=4\times 3\times 2=24$sq.cm