Question

The sides of a $\Delta$ are $7cm,24cm$ and $25cm$. Find its area.

• A. $168c{m}^2$
• B. $84c{m}^2$
• C. $87.5c{m}^2$
• D. $300c{m}^2$

Answer 1

The correct option is B $84c{m}^2$

Let $a=7$cm $b=24$cm $c=25$cm

$S=\frac{a+b+c}{2}=\frac{7+24+25}{2}=28cm$

Now, area of $△=\sqrt{S(S-a)(S-b)(S-c)}$

$=\sqrt{28(28-7)(28-24)(28-25)}=\sqrt{24\times 24\times 4\times 3}=\sqrt{4\times 7\times 7\times 3\times 4\times 3}=4\times 7\times 3=84{cm}^2$