Question

Find the radius of the incircle of a triangle whose sides are $18,24$ and $30$

Answer 1

We know that,

Radius of incircle is$=\frac{Area}{Halfofperimeter}=\frac{△}{s}$

Let $a=18,b=24,c=30$

then $s=\frac{a+b+c}{2}=\frac{18+24+30}{2}=36$

$\therefore △=\sqrt{s(s-a)(s-b)(s-c)}=\sqrt{36\times 18\times 12\times 6}=216$

$R=\frac{△}{s}=\frac{216}{36}=6$