The sides of a triangle are in the ratio 5 : 12 : 13, and its perimeter is 150 m. Find the area of the triangle
Let the sides of a triangle be 5x m ,12x m and 13x m.
Since, perimeter is the sum of all the sides,
$5 x+12 x+13 x=150$
$\Rightarrow 30 x=150$
or, $x=\frac{150}{30}=5$
The lengths of the sides are:
$a=5 \times 5=25 \mathrm{~m}$
$b=12 \times 5=60 \mathrm{~m}$
$c=13 \times 5=65 \mathrm{~m}$
Semiperimeter $(\mathrm{s})$ of the triangle $=\frac{\text { Perimeter }}{2}=\frac{25+60+65}{2}=\frac{150}{2}=75 \mathrm{~m}$
Area of triangle $=\sqrt{s(s-a)(s-b)(s-c)}$
$=\sqrt{75(75-25)(75-60)(75-65)}$
$=\sqrt{75 \times 50 \times 15 \times 10}$
$=\sqrt{562500}$
$=750 \mathrm{~m}^{2}$