Question

The sides of a triangle are 5 cm, 12 cm and 13 cm. Then its area is

• A. $0.0024m^2$
• B. $0.0026m^2$
• C. $0.003m^2$
• D. $0.0015m^2$

Answer 1

Answer: (C)

Using Heron's formula i.e.
$A=\sqrt{s(s-a)(s-b)(s-c)}$
where,
$a=5$ cm
$b=12$ cm
$c=13$ cm
$s=\frac{a+b+c}{2}=\frac{5+12+13}{2}=15$cm
$A=\sqrt{15(15-5)(15-12)(15-13)}$
$A=\sqrt{15\times 10\times 3\times 2}$
$\therefore A=30$ $c{m}^2$
$\therefore A=0.003$ $m^2$